Ashwagandha This adaptogen has been studied for stress and fatigue and small randomised controlled trials (RCTs) suggest that it can possibly benefit people with anxiety. However, evidence for improving cognitive functions like memory, focus, and information processing speed is inconsistent. Dr. Sood stated that it is generally safe for up to 12 weeks but should be avoided during pregnancy as it may induce abortions. Bacopa monnieri This natural supplement is used for improving memory and learning skills. According to Dr. Sood, "Some trials (administering around 300 mg per day for up to 12 weeks) have shown improvements in attention and recall, sometimes even within an hour." However, he also mentions that the results are mixed and inconsistent, since administering higher doses often shows no beneficial results. Ginkgo biloba Ginkgo is rich in antioxidants and believed to reduce inflammation and support brain, heart, and eye health, as per Healthline. Dr. Sood notes that doses of 120-360mg have shown improvement in attention and memory span within hours of consumption. However, the results are inconsistent - longer trials did not show any clear signs of improvement and some studies even showed declines. He also emphasizes that this supplement comes with its side effects - headache and mood changes. Additionally, it also increases the risk of bleeding, especially with anticoagulants. Ginseng Ginseng is rich in antioxidants and is believed to improve focus and support immune system health, according to Cleveland Clinic. Dr. Sood explains that 200-400mg of the supplement can improve attention and memory, but evidence is limited to only a few studies. He also notes, "Long-term benefits remain unclear, and continuous use beyond six months may be unsafe," with side effects that include insomnia, headache, and an upset stomach. Omega-3 fatty acids Omega-3 fatty acids like EPA and DHA are structural fats found in brain cell membranes that support brain function. EPA and DHA from food sources like fishes, walnuts, flaxseeds and eggs are highly beneficial for brain health. According to Dr. Sood, "Supplement trials are mixed, some show benefits at 2-2.5 g per day, others no effect," and he also added, "FDA advises no more than 2 g per day from supplements (3 g per day total considered safe)." Rhodiola rosea This is traditionally used to counter fatigue and improve focus under stress. Dr. Sood states that small trials have shown evidence of reduced fatigue and improved attention with doses of 600mg per day, however evidence is limited and inconsistent. Some studies also suggest that lower doses (up to 370mg per day or less) show better results. Rhodiola rosea is safe for short-term use, but the long-term effects are unknown.