If you need to manage stress or focus, you might look to “nootropics,” cognitive enhancement drugs that promise to help keep you calm and attentive.

These dietary supplements have been shown to improve cognitive function—even if they’re not officially regulated or approved by the FDA. You may already be taking a few: caffeine, red reishi mushrooms, ginseng, turmeric, ginkgo biloba, and Bulletproof coffee are all popular, while natural supplements like creatine, L-theanine and Bacopa monnieri are also being marketed to help promote mental clarity, focus, and information retention.

Synthetic compounds, like Adrafinil and Noopept, last longer and take effect within minutes. By some analyst estimates, the nootropic market could reach $11 billion in America alone by 2024.