Nootropics: What are They?
7 min read

Nootropics: what are they?

AUTHOR: Cliff Harvey, PhD (Clinical Nutritionist & Researcher)


Nootropics are drugs, supplements, or foods and beverages that might improve cognitive functioning, including focus, mood, memory, creativity and motivation. Nootropics are also known colloquially as cognitive enhancers or ‘boosters’. There are several drugs that are purported to improve memory and cognition, but increasing attention is being paid to nutritional supplements, herbs and mushrooms that may improve mental functioning too.


Table of Contents



There are many purported nootropic supplements. Some of the most common and most frequently studied include:


  • Acetyl-L-carnitine
  • Brahmi (Bacopa monnieri)
  • Caffeine and other compounds from coffee, tea and cocoa
  • Lipids (especially DHA from fish oil and medium-chain triglycerides)
  • Fungi (especially Hericium erinaceous – lion’s mane)
  • Acetylcholine precursors (such as lecithin/phosphatidylcholine and citicoline)
  • Astaxanthin
  • Ginkgo (Ginkgo biloba)
  • Korean ginseng (Panax ginseng)
  • Multivitamins and minerals
  • Sage (Salvia officinalis)
  • Spearmint (Mentha spicata)


The nootropics listed above are common either as foods, supplements, or traditional medicines with a long history of use. But do they work? Clinical Nutritionist Cliff Harvey discusses the evidence for five well known nootropics below.


1. Acetyl-L-carnitine


Acetyl-carnitine is a naturally occurring substance formed in cells when an acetyl group is added to carnitine. Carnitine (created from the amino acid lysine) aids the transport of fatty acids into the mitochondria to be used for energy. Acetyl-carnitine is more easily absorbed and can cross the blood-brain barrier more easily than L-carnitine. Acetyl-L-carnitine has been shown to reduce fatigue, anxiety and depression and age-related cognitive defects3.


2. Brahmi (Bacopa monnieri)


Brahmi (water hyssop, bacopa, Indian pennywort) is a perennial creeping herb native to India, Australia, Europe, Africa, Asia and the Americas. It is a traditional Ayurvedic medicinal herb with use as a cognition and memory enhancer5. Several studies have demonstrated the potential for brahmi to improve cognition. It is thought to do so by antioxidant neuroprotection, increasing choline, reducing β-amyloid, increased cerebral blood flow, and by modulating neurotransmitters such as acetylcholine, serotonin and dopamine5. In a 2008 randomized controlled trial 160 mg brahmi extract (equivalent to 4 g dried herb) given to volunteers for 90 days resulted in significant improvements to memory accuracy6. A recent (2014) meta-analysis has summarized the findings from nine existing studies (437 participants), showing improved cognition and reaction times7.


3. Caffeine


Caffeine is a well-known cognitive enhancer. Reviews of the evidence show that caffeine improves attention, vigilance, reaction times and problem-solving (especially in sleep-deprived people)8,9. Large scale reviews of the evidence show significant benefits from caffeine for positive mood and lower perceived fatigue. Doses of 12.5mg up to 400-600mg (<1 to 4-6 cups per day of coffee) provide a positive effect9,10, however, greater doses do not always provide greater benefits to cognition and mood, and typically, the first cup provides the majority of benefits10. Interestingly, habitual users appeared to experience greater cognitive or mood effects compared with low/non‐users10. Tea and coffee both produce similar benefits to mood and cognition10.


Coffee, tea, caffeine and cognitive decline and dementia


In addition to its acute effect on mood and cognition, caffeine-containing beverages may be protective against cognitive decline and dementia11.

Tea constituents other than caffeine (L-theanine and epigallocatechin gallate) might also improve cognition. A review of the research in this area suggested that caffeine combined with theanine (as found in tea) improved alertness and attention more than caffeine alone12.


4. Lipids

Omega-3 Fatty Acids


The omega-3 fatty acids, DHA and EPA, play an important role in brain development and healthy functioning of the brain and central nervous system. DHA, in particular, makes up the majority of the polyunsaturated fat content of the brain, comprising of over 50% of the plasma membrane of neurons. It is also essential to the functioning of the brain and optimizing cognition and mood30. Omega-3 fats are linked to reduced mental fatigue31, improved memory and cognition and reduced cognitive decline32,33,  reduced rates of depression and improved structural integrity of the brain34,35. Additionally, DHA has also been found to improve cognition and behavior in children36.


Medium-chain triglycerides


Medium-chain triglycerides (MCT) are naturally occurring fats found in small amounts in dairy products and greater amounts in coconut oil. They are also commonly used as isolated supplement oils. MCT supplemented diets improve mental performance in those with Alzheimer’s Disease and age-related cognitive decline37,38, and a single dose of 20g MCT has been shown to improve cognition39.


It’s important to note that if you are considering the use of an MCT oil supplement, it is important that you start with a small dosage and scale up your dose slowly. The reason for this is because having too much MCT oil too quickly can cause gastrointestinal upset.


5. Fungi


Hericium erinaceus (lion’s mane) mushroom is an edible and medicinal mushroom native to North America, Europe and Asia belonging to the tooth fungus group. Lion’s mane has been shown to increase ‘nerve growth factor’40, which helps nerves and brain cells to grow and repair41-46. Because of this brain-repair effect, lion’s mane is being considered as one of the most promising preventative treatments for Alzheimer’s Disease and dementia47,48. It has also been demonstrated to significantly improve mood after four weeks of treatment42 and improve cognitive function49. Lion’s mane might also improve physical performance by reducing perceived fatigue50.


References available upon request.