Please share this page

author: Dr. Kevin Curran

published: 9-17-2016

Top 16 natural brain stimulants and cognitive enhancers.

Everyone wants to function at their highest capacity. As you move through your day, it’s certainly helpful to feel energized and focused.

So how do we do maintain high energy levels?

First and foremost, there is no substitute for a good night’s sleep.

Exercise, go to bed early, wake up and attack the day. These basic lifestyle choices will do much to boost your brain power and keep you focused throughout the day.

In addition, our energy level and mental powers are influenced by the foods we eat and the beverages we drink.

Fortunately, we share this planet with many edible plants and mushrooms that can energize our body and activate our minds.

Below we describe the 16 most popular natural stimulants for our mind and body.

  • All of the brain enhancing compounds discussed below are naturally occurring in plants (or mushrooms.)
  • All of these natural stimulants are legal and do not require a prescription.

This page on natural brain stimulants is intended as a general educational resource. Please keep the following thoughts in mind:

  • These plants have demonstrated their health and/or cognitive benefits in scientific publications. However, that doesn’t mean the plant will do anything for you. Everybody has their own individual genome and their own individual physiology. Ultimately, you have to find what works best for your body.
  • Many of these plants have not been reviewed by the FDA. For any safety concerns, consult with your physician. WebMD and this Memorial Sloan website are excellent resources for exploring any herb-drug interactions or side effects associated with these plants.


Any self-respecting list of natural stimulants has to begin with coffee. Coffee remains one of the most commonly consumed beverages in the world.

Coffee beans are actually seeds from the fruit of a green, leafy shrub from the Rubiaceae family (see photo). The two species of Coffea shrub most commonly grown for coffee beans are Coffea arabica and Coffea canephora. Both species are native to Africa.

  • Coffea arabica is native to the southwestern highlands of Ethiopa, Sudan and Kenya.
  • Coffea canephora is native to the upland forests of Ethiopa.

Coffee is stimulating because it contains 3 different xanthine allakoids: caffeine, theobromine and theophylline.

Xanthines are a group of chemicals that feature a circle structure composed of nitrogen and carbon atoms. They are well known for their ability to stimulate the human body.

As most people know, the primary stimulant in coffee is caffeine.

So, how does caffeine work?

Caffeine is a small molecule that’s officially called an adenosine antagonist. The activity of our brain cells are regulated by adenosine signalling. As we go about our day, adenosine builds up in our brain. Once our adenosine reaches a certain level, we begin to feel sleepy. Caffeine steps in and prevents the sleepy effect.

Caffeine can physically block adenosine from binding to its receptors. Once adenosine signalling is blocked – dopamine and glutamate signals take over. The net effect is that we no longer feel sleepy. Instead, we feel alert and energized.

list of stimulants

Coffea arabica illustration

boosting mental focus

The chemical structure of caffeine.

Coffee also contains another alkaloid chemical called theobromine. Theobromine stimulates our heart and acts as a subtle nervous system stimulant. Furthermore, when our liver breaks down caffeine, more theobromine and another alkaloid named theophylline is produced as metabolite by-products.

Kimera Koffee is interesting because the ground coffee bean is combined with other brain-stimulating nootropics (L-theanine, alpha-GPC and taurine).


Caffeine also acts as a bronchodilater. This means caffeine can increase airflow in your lungs. So…if you’re having an asthma attach and can’t find your inhaler, reach for the nearest cup of coffee. You should get some relief.

Coffee is not the only plant that contains caffeine. Guarana, kola nut and mate tea also contain high levels of stimulating caffeine. We’ll discuss these plants later.

Return to our main list of natural stimulants.


Huperzine-A is an interesting chemical. Its often described as a natural nootropic.

Nootropics are smart drugs or cognitive enhancers. They are generally synthesized in laboratories and are thought to improve focus, memory, and cognition in healthy individuals.

Huperzine-A is considered a natural nootropic because this chemical is produced naturally by a plant called the toothed fir-moss (see photo).

The scientific name for this moss is Huperzia serrata. It belongs in an ancient group of plants called the lycopods. Hyperzia serrata grows natively in Japan and southeast Asia.

The Huperzine-A chemical is classified as an acetylcholinesterase inhibitor. That’s a long word that won’t mean much to most people.

To make a long story short, acetylcholinesterase inhibitor means that Huperzine-A can prevent the breakdown of acetylcholine. In general, this is a good thing, since our brain and our muscles need acetylcholine in order to communicate and operate properly.

natural nootropics

Photo: Keisotyo (CC BY-SA 3.0)

Huperzine-A naturally occurs in this fir-moss plant

In theory, if more acetylcholine stays in the brain – then there will be an improvement in brain function. A published clinical study describes how Huperzine-A helps prevent the loss of mental function in Alzheimer’s patients. You can read more about this recent study here. Additional research performed on Huperzine-A has explored its ability to improve memory, block NMDA receptors and prevent cognitive decline.

For all these reasons, Huperzine-A is currently sold as a popular brain stimulant supplement called Alpha Brain. Alpha Brain capsules contain Huperzine-A (and 3 other plant-based ingredients that also enhance mental performance). Onnit, the company that produces Alpha Brain, has published some clinical data to support their claims, you can review that research here.

Return to our list of natural stimulants.


Have you ever noticed that drinking tea can be stimulating while also calming? Well, it seems that L-theanine is the chemical that’s responsible for that effect.

In the 1950s, scientists discovered that leaves from the tea plant (Camellia sinensis) naturally produce this interesting compound. If you drink a cup of green tea, you’re getting about 30 mg of caffeine – but you’re also getting about 10 mg of L-theanine.

L-theanine is structurally similar to the amino acids: glutamate and glutamine. This makes sense, as L-theanine also contributes the savory, umami type of flavor that can be tasted in many green teas.

legal stimulants

L-theanine is found in a cup of green tea

L-theanine has many reported benefits – including arousal, alertness and cognition.

Interestingly, theanine is also thought to reduce anxiety symptoms. In contrast to caffeine, L-theanine does not make people jittery.

One report worth reading describes how the combination of caffeine and L-theanine led to improvements in brain function, including:

  • faster reaction time
  • faster working memory
  • more accurate sentence verification

A separate neurobiology paper reviews the proposed mechanism of action for L-theanine. In other words, the author attempts to explain how this compound could stimulate our brain while also keeping us calm.

To summarize their findings…

The improvements in learning and memory are attributed to the regulation of NMDA related long term potentiation. Long term potentiation (LTP) is a brain activity that helps form memories. Meanwhile, the calming effect or anxiety-reducing effect may be related to L-theanine’s ability to regulate serotonin, dopamine and other inhibitory neurotransmitters in specific regions of our brain (Lardner, 2014).

I drink black tea, which delivers about 24 milligrams of L-theanine. Although, to really get the L-theanine effect, I take these 200 milligram capsules.

Return to our list of natural stimulants.

Coconut oil

Coconut oil is pressed from the soft meat of mature coconuts. These coconuts grow on the coconut palm tree (Coccos nucifera).

Coconut oil is unique in that – it has a very amount of saturated fats. In fact, natural coconut oil is about 90% saturated fat.

As you may remember, we are supposed to avoid saturated fats because they can lead to high cholesterol levels. Well, as it turns out, not all saturated fats are created equal. Certain types of saturated fats offer positive health benefits.

Much of the saturated fats in coconut oil are called medium-chain triglycerides, or MCTs. According to specialists, MCTs are especially easy for our body to digest and convert into energy. Additionally, at least one report has been published linking coconut oil to weight loss.

brain function

A spoonful of coconut oil

Dr. Dom D’Agostino describes the connection between coconut oil and energy levels, ketosis and fat-burning in our body. If you’re interested in the subject you can listen to this podcast discussion between Tim Ferris and Dom D’Agostino.

Personally, I’m in the habit of mixing coconut oil into my morning coffee. This bottle of MCT coconut oil is derived 100% from coconuts and delivers a clean energy supply. It contains the C8, C10 and Lauric acid forms of MCT oil.

Return to our list of natural stimulants.

Gotu kola

Gotu kola is a small, delicate herb from the Parsley family of plants. This is the same family that includes the carrot. This scientific name for gotu kola is Centella asiatica. As you may expect from the species name, gotu kola is native to the swampy, wetlands of Asia.

The leaves and stems of gotu kola have been used in traditional medicine for a long time. This herb appears in the ancient texts of Traditional Chinese Medicine, traditional African medicine and Ayurvedic medical books from India.

Historically, gotu kola has been used for many different ailments (skin conditions, varicose veins), however we are most intrigued with its ability to help enhance mental clarity.

natural cognitive enhancers

Photo: Shashidhara halady (CC BY-SA 4.0)

Gotu kola plant growing in India

Recent reports have explored the ability of gotu kola to improve brain function and focus.

One report found that use of gotu kola could strengthen brain function in a group of healthy elderly people. Their overall mood and their working memory improved upon treatment with gotu kola extract.

Another report explored the ability of gotu kola to help maintain mental focus and decrease anxiety. To test these features, the scientists used the acoustic startle response test. Human subjects were given a 12 gram dose of gotu kola (this is a very high dose). The authors concluded that gotu kola did result in improvements in the startle response, suggesting the plant can help reduce anxiety and and enhance focus.

Sidenote: Gotu kola and kola nut are NOT the same thing. They are completely different plants. Kola nut contains high amounts of caffeine, however, there is no caffeine in gotu kola. In fact, biochemists have determined that the active chemical in gotu kola is a triterpenoid compound named asiaticoside.

Return to our list of natural stimulants.

Kola nut

The kola nut is the seed of the kola tree. This tree is native to tropical rain-forests throughout Africa. In Nigeria and other west African nations, the chewing of the kola nut has become integrated into traditional ceremonies as well as casual social events. Similar to coffee, the kola nut is packed with caffeine.

Because of its caffeine content, the kola nut is used to combat fatigue and mental slowness. Its also used in food and drinks to add flavor and color.

Kola nut played an important role in the design of one of the most famous sodas in the world, Coca-Cola.

In 1886, John Pemberton, a pharmacist living in Georgia, combined carbonated water with extract from kola nut and the Peruvian coca leaf. The coca leaf actually provided this drink with a small amount of cocaine. This concoction soon became quite popular in the local soda fountain shops. John named his creation Coca-Cola.

The ‘Cola’ in the name is a tip of the hat to the kola nut ingredient. The ‘Coca’ is an acknowledgement of the cocaine plant. As you might imagine, neither kola nut nor the Peruvian coca leaf remain in Coca-Cola today.

Return to our list of natural brain stimulants.

enhance concentration

Illustration of the kola nut plant from Köhler’s Medicinal Plants (1887).

Rhodiola rosea

Rhodiola rosea is a rugged plant from the stonecrop family. I say rugged because the plant is often found growing on windy, seaside cliffs as well as mountain tops across northern Asia.

Siberians have been using this herb for centuries as a means to deal with the physiological stress of their cold winter season. The plant is now widely used as a means to reduce mental fatigue.

Russian biochemists performed a lot of work on Rhodiola throughout the past 100 years. Eventually, they isolated a chemical called salidroside from the plant. Salidroside is believed to be responsible for many of the physiological effects of Rhodiola.

Russians scientists were also the first to describe the plant as adaptogenic. This means the plant can reduce stress and encourage homeostasis within the body.

natural stimulants

Photo: Amazonia Exotics U.K. (CC BY-SA 4.0)

New leaves for this Rhodiola rosea

Clinical trials for Rhodiola can be contradictory. That said, there are a handful of publications that demonstrate Rhodiola’s capacity to clear away mental fog.

A Phase III trial performed in Sweden tested mental performance on a group of 60 human subjects. The patients that received Rhodiola reported significant improvements as determined by the Pine’s burnout scale (a test of fatigue) and a test for mental health (SF-60). The authors conclude that repeated use of Rhodiola lends an anti-fatigue effect that can increase mental performance.

Return to our list of natural stimulants.


Guarana is a climbing plant in the Maple family. This bushy plant grows comfortably in Brazil and the broader Amazon Basin.

Similar to coffee and kola nut, guarana is packed full of caffeine and is well-respected for its ability to reduce fatigue.

Consuming caffeine leads to the stimulation of the central nervous system, heart stimulation, increase in blood pressure and the stimulation of skeletal muscles.

Guarana also contains theobromine and theophylline.

Many people will feel a different type of buzz from coffee, mate, kola nut or guarana. This is largely attributed to 2 things:

  1. difference in the amount of caffeine in each plant
  2. varying ratios of theobromine and theophylline in each plant

Each plant has a unique ratio of these secondary xanthines. Subtle differences in the ratio of caffeine, theobromine and theophylline will effect the way the drink is perceived.

Lately, guarana has been showing up in lots of different energy drinks. You may hear people refer to the stimulating guarana compound as guaranine. Don’t be fooled, guaranine is just another name for caffeine.

Return to our list of natural mental stimulants.

improve energy and focus

Illustration of the guarana plant from Köhler’s Medicinal Plants (1887).

Lion’s mane

Lion’s mane is an edible and medicinal mushroom. You may have already eaten lion’s mane in a Chinese dish. It’s often used as substitute for pork in Asian vegetarian meals.

Lion’s mane grows in clumps along the sides of hardwood trees in North American and European forests. This odd looking mushroom also goes by the name bearded tooth mushroom. If you’ve ever seen the lion’s mane, then that name will make a lot of sense. This odd creature is shaped like a pile of long white teeth (see photo).

Its scientific name is Hericuium erinaceus.

Lately, there’s been a lot of medical interest in this mushroom. A collection of scientific papers have explored the connection between lion’s mane and brain activity.

The results suggest that lion’s mane can stimulate new brain cells and enhance cognitive function. Paul Stamets, the famed mycologist, wrote a nice summary of these scientific findings in this Huffington Post article.

natural brain stimulants

Photo: Lebrac (CC BY-SA 3.0)

Lion’s mane mushroom growing on fallen tree

Here are a few highlights from the Paul Stamet article:

A Japanese research group performed a trial on a group of adults with mild cognitive impairment. Cognition is defined as the action of acquiring new knowledge and thinking. The researchers wanted to know if treatment with lion’s mane would result in cognitive improvements in this group. The HDS-R Hasegawa Dementia Scale was used to measure cognition. After 8 weeks of treatment, the group taking lion’s mane showed significant improvements in terms of their cognitive issues. These results suggest that lion’s mane can improve mental processing.

Another report looked at the ability of lion’s mane to encourage brain cell activity. In order for our brain cells, or neurons, to function properly – they require communication with a small protein called neurotrophic growth factor (NGF). Biologists tested the ability of four different mushrooms to activate NGF expression. Lion’s mane was the only mushroom that caused a positive effect on NGF activity. The authors conclude that certain chemicals found in lion’s mane can activate NGF gene expression.

Activated NGF levels would certainly have an effect on brain cell activity. More research is needed, but it certainly seems that there’s a connection between our brain’s performance and this odd shaped mushroom.

Next time you need an interesting veggie for a stir fry dinner, perhaps try out this mushroom. You can generally find the lion’s mane in the produce section of most gourmet supermarkets.

Return to our list of natural stimulants.


Mate is a traditional drink from South America. The leaves of the yerba mate plant (Ilex paraguariensis) are chopped up, steeped in hot water and drank as a hot beverage. Mate also goes by the name Yerba Mate and chimarrão (Portugese).

The first people to drink mate were the indigenous Guaraní people living in southern Brazil. After European colonization of Brazil in the 16th century, the drink spread throughout Spain and then into much of the world.

If you want to be traditional, you’ll hold your mate in a hollowed out gourd and drink the concoction through an ornate straw called a bombilla (see photo).

Mate is well known for its stimulating effects. The leaves of the yerba mate plant contain the same xanthine alkaloid compounds as coffee:

  • caffeine
  • theophylline
  • theobromine

When people talk about the mateine chemical, they are just referring to caffeine from the mate plant.

Return to our list of natural stimulants.

brain food

Photo: Jorge Alfonso (CC BY-SA 2.5)

Mate leaves prepared in a traditional Calabash gourd

Oat Straw

Oats are an unlikely source of mental stimulation.

But sure enough, many people skip the crash and burn effect of caffeine and turn to oat straw for a more sustained energy boost.

The green oat material is from the common oat plant, Avena sativa. This is the same plant that ends up in our breakfast cereals and granola bars. Apparently, when the plant is harvested earlier in the season during the green, flowering stage, there are certain properties in the milky stage grain that help activate our brains.

improve concentration

Norwegians harvesting oat straw (1890)

A handful of experiments suggest that consuming oat straw will increase energy and enhance mental function.

One group used EEG spectral frequencies to show that eating oat straw led to heightened electrical activity in the left fronto-temporal area of the brain. This type of brainwave activity is associated with being alert and mentally aroused. The authors conclude that oat straw may very well be effective at raising cognitive performance.

I’ve never tried oat straw, but I’ve heard it supplies a more subtle, sustained energy and that this energy can last throughout the day.

Return to our list of brain stimulants.


Ashwagandha is the common name for Withania somnifera.

This is a short, leafy plant in the nightshade family. Nightshade plants also include: tomatoes, potatoes and eggplant.

If you have any familiarity with Ayurvedic medicine, then you’ve likely heard of ashwagandha. Ayurveda is a traditional system of medicine that originates from India. The ashwagandha plant is used by practitioners of Ayurvedic medicine to address a range of conditions.

The red berries and leaves are applied to treat skin conditions. The long, slender roots are ground up into a powder. This powder is mixed with milk and honey and drunk in response to stress, pain, epilepsy, arthritis, ext.

Ashwagandha is often referred to as an adaptogen, as its thought to help our body adjust to stress. Interestingly, this plant is also used to help reduce fatigue and improve mental energy.

One study examined brain function in a group of patients suffering from bipolar disorder. The scientists found that ashwagandha provided significant improvements in 3 different cognitive tests (auditory-verbal working memory, Flanker response time and social cognition response.)

The authors acknowledge this data is preliminary but suggest ashwagandha can help cognitive function in patients suffering from bipolar disease.

best supplements for concentration and focus

Photo: Roger Culos (CC BY-SA 3.0)

Fruit of the ashwagandha plant

Ashwagandha has also been used to reduce fatigue. This fatigue effect has been explored in a study involving breast cancer patients.

Cancer patients are often treated with chemotherapy to kill off their cancer cells. One of the side effects of chemotherapy is fatigue. This small study showed that breast cancer patients undergoing chemotherapy can experience a reduction in fatigue if treated with ashwagandha. While this report is intriguing, it would be nice to see this effect repeated in a larger group of healthy individuals.

Return to our list of natural stimulants.


Bacopa monnieri is a low, creeping water plant that is native to the wetlands of southern India. This small herb grows comfortably in swamps and ponds.

Similar to Ashwagandha, Bacopa is a popular medicinal plant within the Ayurvedic system of medicine. Indians refer to Bacopa as Brahmi. This is a tip of the hat to Brahma, the Creator God of Hinduism.

For centuries, Ayurveidc practitioners have made the claim that Bacopa can improve mental function (i.e. act as a cognitive enhancer).

This plant is used in response to ADHD, poor memory, Alzheimer’s disease and anxiety disorders. Recent scientific reports suggest there is a biological basis behind some of these historical health claims.

best brain supplements

Photo: Forest & Kim Starr (CC BY 3.0)

Bacopa growing in a swamp

One clinical trial showed evidence that use of Bacopa can enhance free memory recall in healthy adults. Another published report demonstrates some improvement in memory and hand-eye coordination among a group of young children taking Bacopa.

How does Bacopa work?

The short answer is…we don’t really know how Bacopa works.

Using laboratory animals, scientists have observed Bacopa increasing cerebral blood flow and inhibiting an enzyme that degrades acetylcholine. Both of these effects would certainly alter mental activity.

Its likely that the active chemicals within Bacopa monnieri are a series of triterpenoid glycosides, called bacosides. Chemists have isolated these chemicals from the plant. However, at this moment, it remains unclear whether the bacosides are responsible for any memory enhancement.

Nootropic supplement companies commonly include Bacopa in their cognitive enhancing formulas.

Return to our list of natural stimulants.

Artichoke extract

Who doesn’t like a good artichoke dip? Its the perfect compliment to corn chips. My parents love artichoke, so I grew up dipping steamed artichoke leaves in heated butter.

My parents didn’t know it at the time, but they were feeding me a brain activating food.

The leaves of the common artichoke (Cynara scolymus) are a rich source of PDE4 inhibitors. Now, I know what you’re thinking. What on earth is a PDE4 inhibitor??

Well,  it turns out – PDE4 inhibitors can help us stimulate our brains and form stronger memories.

PDE4, also known as phosphodiesterase-4, is an enzyme that works in our brain cells to break apart cAMP molecules. We need cAMP molecules in our brain cells. They help us form memories through LTP (long-term potentiation).

A PDE4 inhibitor will prevent the breakdown of cAMP. That leaves us with higher levels of cAMP in our brain. Our brain then benefits from this abundance of cAMP.

herbal stimulants

Photo: Jamain (CC BY-SA 3.0)

An artichoke blooming in a French pasture

Scientific reports demonstrate how a PDE4 inhibitor can reduce fatigue and also lead to an increase in cognition (mental processing).

So, next time someone shows up at your party with artichoke dip, be sure to thank them for making you a little bit smarter.

Sidenote: Artichoke extract is often taken in combination with forskolin. This report found that the 2 substances work synergistically in our hippocampus to induce LTP / memory formation. Forskolin is found naturally in the root of the Indian Coleus plant. This chemical can also boost cAMP levels in our brain. I haven’t seen enough safety information about forskolin, so I’m not going to discuss it any further on this page.

Return to our list of natural stimulants.

American ginseng

Ginseng is a leafy plant with an odd shaped root. Its cultivated all across the world but is most famous for its prominent role in Traditional Chinese Medicine.

There are actually 3 types of medicinal ginseng.

  • American ginseng (Panax quiquefolius)
  • Asian ginseng (Panax ginseng)
  • Siberian ginseng (Eleutherococcus senticosus)

Each of these ginseng species has their own internal biochemistry. And each of these species are used for different reasons by different people around the world.

For the sake of this article, I am focusing on American ginseng (Panax quiquefolius), as this species demonstrates the ability to reduce fatigue and improve mental focus.

American ginseng is native to North America, although the plant is now widely cultivated throughout China. As you can see in the photo, this species has a thick root that forks in the middle.

brain boost

Sketch of American ginseng from American Medical Botany (1820)

Similar to Asian ginseng, American ginseng is full of saponin compounds. These compounds are referred to as ginsenosides. Ginsenosides are the major biologically active chemicals found in American ginseng.

So, what are these ginsenosides doing?

Well, we don’t really know. However, this plant has a devout group of followers that swear by its powers. Ginseng is regarded by many to be a panacea. A panacea is a cure-all type of herb.

In general, I’m skeptical when I hear that a plant can help all sorts of problems with the human body. However, in regards to energy levels and brain stimulation, American ginseng seems to be effective.

American ginseng is thought to reduce fatigue. To test this claim, a group of scientists designed an experiment to ask whether treatment with American ginseng could reduce the fatigue felt by cancer survivors.

Fatigue, or persistent low energy, is one of the many challenges associated with fighting cancer. It seems that the American species of ginseng can help with this issue.

A multi-site, double-blind trial was performed on 364 cancer survivors from 40 different institutions. Patients were tested with the Fatigue Symptom Inventory-Short Form (MFSI-SF) at 4 and 8 weeks after ginseng treatment began.

The authors of this study conclude that – after 8 weeks – the patients whom received 2 grams of American ginseng were significantly less fatigued compared to the placebo control group. Additionally, no toxic side effects were observed with the ginseng treated group.

Sidenote: A 364 person trial is a large endeavor. Its very rare to see a 100+ patient study performed outside of the big-money, pharmaceutical industry.

Another report examined the cognitive effect of American ginseng on a group of 32 healthy adults. Compared to a placebo-controlled group, patients that received an extract of American ginseng reported significant improvements in working memory (WM).

Return to our list of natural stimulants.


Maca is a fascinating plant from the Peruvian highlands. The ancient Inca people of Peru were especially fond of this plant. According to legend, Inca warriors routinely ate maca root before they charged into battle. The plant was believed to boost their strength and endurance.

The Incas must have had the right idea, because now – 600 years later – professional athletes still routinely take maca supplements. Sportsmen report feeling improvements in strength and endurance after eating this plant.

Personally, I am now in the habit of adding a tablespoon of maca to my coffee.

natural remedies for focus and concentration

Thick roots of the maca plant

This small study explored the claim that maca can enhance athletic performance. A group of cyclists rode for 40 km on their bike. These athletes then took a maca supplement for 14 days and repeated the 40 km ride. After taking maca extract, the cyclists performed significantly better than their initial baseline ride. While this is only a small, preliminary human trial. The results do corroborate with our historical evidence regarding maca usage by the Inca community.

I previously wrote a longer article on the additional health benefits of maca (female sex drive, male libido and menopause issues). In this article, I also review 4 popular brands of maca supplements and I discuss the different factors to consider when choosing a maca supplement. Click here to read this article.

Return to our list of natural stimulants.

This concludes our list of natural brain stimulants.

The list is a work in progress, so please bookmark the page and return often.

I’ll be updating the page each year as new research is published on these plants.

Thanks for stopping by!


American ginseng

Scholey, Andrew, et al. “Effects of American ginseng (Panax quinquefolius) on neurocognitive function: an acute, randomised, double-blind, placebo-controlled, crossover study.” Psychopharmacology 212.3 (2010): 345-356.

Barton, Debra L., et al. “Wisconsin Ginseng (Panax quinquefolius) to improve cancer-related fatigue: a randomized, double-blind trial, N07C2.” Journal of the National Cancer Institute 105.16 (2013): 1230-1238.

Rhodiola rosea

Olsson, Erik MG, Bo von Schéele, and Alexander G. Panossian. “A randomised, double-blind, placebo-controlled, parallel-group study of the standardised extract shr-5 of the roots of Rhodiola rosea in the treatment of subjects with stress-related fatigue.” Planta medica 75.02 (2009): 105-112.


Stone, Mark, et al. “A pilot investigation into the effect of maca supplementation on physical activity and sexual desire in sportsmen.” Journal of ethnopharmacology 126.3 (2009): 574-576.

Artichoke extract

Lelkes, Z., et al. “Rolipram, an antidepressant that increases the availability of cAMP, transiently enhances wakefulness in rats.” Pharmacology Biochemistry and Behavior 60.4 (1998): 835-839.

Barad, Mark, et al. “Rolipram, a type IV-specific phosphodiesterase inhibitor, facilitates the establishment of long-lasting long-term potentiation and improves memory.” Proceedings of the National Academy of Sciences 95.25 (1998): 15020-15025.

Lion’s mane

Mori, Koichiro, et al. “Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double‐blind placebo‐controlled clinical trial.” Phytotherapy Research 23.3 (2009): 367-372.

Mori, Koichiro, et al. “Nerve growth factor-inducing activity of Hericium erinaceus in 1321N1 human astrocytoma cells.” Biological and Pharmaceutical Bulletin 31.9 (2008): 1727-1732.


Stough, Con, et al. “Examining the nootropic effects of a special extract of Bacopa monniera on human cognitive functioning: 90 day double-blind placebo-controlled randomized trial.” Phytother Res 22.12 (2008): 1629-34.

Pase, Matthew P., et al. “The cognitive-enhancing effects of Bacopa monnieri: a systematic review of randomized, controlled human clinical trials.” The Journal of Alternative and Complementary Medicine 18.7 (2012): 647-652.

Sivaramakrishna, Chillara, et al. “Triterpenoid glycosides from Bacopa monnieri.” Phytochemistry 66.23 (2005): 2719-2728.


Mishra, Lakshmi-Chandra, Betsy B. Singh, and Simon Dagenais. “Scientific basis for the therapeutic use of Withania somnifera (ashwagandha): a review.” Alternative medicine review 5.4 (2000): 334-346.

Chengappa, KN Roy, et al. “Randomized Placebo-Controlled Adjunctive Study of an Extract of Withania somnifera for Cognitive Dysfunction in Bipolar Disorder.” The Journal of clinical psychiatry 74.11 (2013): 1076-1083.

Biswal, Biswa Mohan, et al. “Effect of Withania somnifera (Ashwagandha) on the development of chemotherapy-induced fatigue and quality of life in breast cancer patients.” Integrative cancer therapies 12.4 (2013): 312-322.

Gotu kola

Wattanathorn, Jintanaporn, et al. “Positive modulation of cognition and mood in the healthy elderly volunteer following the administration of natural mental stimulant Centella asiatica.” Journal of ethnopharmacology 116.2 (2008): 325-332.

Bradwejn, Jacques, et al. “A double-blind, placebo-controlled study on the effects of Gotu Kola (Centella asiatica) on acoustic startle response in healthy subjects.” Journal of clinical psychopharmacology 20.6 (2000): 680-684.

Wan, JingYuan, et al. “Antipyretic and Anti‐inflammatory Effects of Asiaticoside in Lipopolysaccharide‐treated Rat through Up‐regulation of Heme Oxygenase‐1.” Phytotherapy Research 27.8 (2013): 1136-1142.


Lardner, Anne L. “Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders.” Nutritional neuroscience 17.4 (2014): 145-155.

Haskell, Crystal F., et al. “The effects of L-theanine, caffeine and their combination on cognition and mood.” Biological psychology 77.2 (2008): 113-122.

Lardner, Anne L. “Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders.” Nutritional neuroscience 17.4 (2014): 145-155.

Huperzine A

Xing, Shu-huai, et al. “Huperzine A in the treatment of Alzheimer’s disease and vascular dementia: a meta-analysis of natural brain stimulants.” Evidence-Based Complementary and Alternative Medicine 2014 (2014).

Oat straw

Dimpfel, Wilfried, Charlotte Storni, and Marian Verbruggen. “Ingested natural stimulant oat herb extract (Avena sativa) changes EEG spectral frequencies in healthy subjects.” The Journal of Alternative and Complementary Medicine 17.5 (2011): 427-434.

Coconut oil

Assunçao, Monica L., et al. “Effects of dietary coconut oil on the biochemical and anthropometric profiles of women presenting abdominal obesity.” Lipids 44.7 (2009): 593-601.