What a fun-looking word: nootropics. It refers to any type of compound or food that has the ability to improve your mental abilities, including your memory, ability to focus, motivation, or even mood. While the general category most definitely includes smart drugs, neuro-enhancing supplements fit the bill as well. Daily, neuroscientists are acquiring a more nuanced understanding of the brain, the result being many new pharmaceutical drugs which target exact regions of the brain are in the works. The very same knowledge, though, might reveal how particular supplements might do an equally good job of improving brain function over the long haul.

Why go for prescription-strength when you can get the same by shopping the vitamin aisle?

In that spirit, here’s a list of dietary supplements you could investigate for their potential use as a nootropic. Remember: Do your research and ask a doctor’s advice before popping any pill, natural or not. More importantly, not all dietary supplements are created equal, with some brands including additives you may not want (or are allergic to), so it’s important to vet any unfamiliar manufacturers.

Creatine is an old favorite among gym rats, who use it to enhance their sports performance, but over the past decade or so, the supplement’s neuro-enhancing abilities have been demonstrated as well. In one placebo-controlled study, researchers tested the hypothesis that 5 grams a day for a six-week period would enhance intelligence test scores while also improving memory. They enlisted the help of 45 young adult, vegetarian subjects and found the supplement had a significant positive effect on both working memory and intelligence, particularly with regard to tasks that require speed of processing. Though they tested vegetarians, the researchers would “expect to see a beneficial effect of creatine supplementation on brain performance in most omnivores apart from those who consume very high amounts of meat.”

Theanine (or more commonly L-theanine) is found in green tea and mushrooms and also sold as a dietary supplement in the United States. In fact, the Food and Drug Administration has granted it GRAS status (generally recognized as safe). According to various scientific studies, theanine has been found to affect the levels of some neurotransmitters, to prevent beta-amyloid-induced brain dysfunction, and to protect against stroke. L-theanine is even said to improve sleep quality in boys with attention deficit hyperactivity disorder. In terms of potential nootropic uses, several small studies indicate a combination of L-theanine and caffeine can improve cognitive performance, particular in the areas of focus and alertness. Apparently, though, the effects may not be long-lasting.

Passionflower is derived from the above ground parts of the plant. Primarily, people take it for its anti-anxiety effects, which have been proven in smaller scientific studies though not yet confirmed in large scale studies. Some other people use it to treat insomnia as well as neuralgia and withdrawal symptoms while coming off opiates or benzodiazepines. In patients undergoing surgery as well as those about to be treated by a dentist, passionflower has been effectively used to reduce apprehension.

DHA, an omega-3 fatty acid found in fish and seaweed, can improve your memory while protecting against certain psychiatric disorders. Various surveys of people with major depression indicate they have depleted levels of omega-3 fatty acids and one large study found depressive symptoms were significantly higher among infrequent fish consumers. However, no study has ever proven omega-3 fatty acid supplementation effective in relieving major, moderate, or even mild depression. That said, some data suggest it is a safe preventive measure and may reduce the risk of progression of certain psychiatric disorders. While one review of scientific studies found that DHA supplements significantly improves cognitive development in infants — though does not improve cognitive performance in children, adults, or the elderly — another review shows it can protect against mild cognitive impairment, dementia, and the risk and progression of Alzheimer's disease in the elderly.