L-Theanine 200 mg with Suntheanine

Sports Research's L-Theanine is one of Amazon's best-selling single-ingredient theanine supplements. Each softgel delivers 200 mg of Suntheanine, a branded form of L-theanine, suspended in organic virgin coconut oil, and one softgel is the full serving.

L-theanine is an amino acid found in tea leaves, and it is one of the better-supported options for people who want to take the edge off stress without sedation. In a small 2019 randomized, placebo-controlled crossover trial co-authored by researchers from Suntheanine's maker, 30 healthy adults taking 200 mg a day for four weeks saw their anxiety, depression and sleep-quality scores improve, and several sleep measures beat placebo. A 2025 systematic review of 13 trials concluded that 200-450 mg a day appears to be a safe and effective way to support sleep in adults. This product's 200 mg dose sits at the low end of that range, so some people take it in the evening for wind-down and others during the day for calm focus.

The label is about as clean as supplements get: one active ingredient, with coconut oil, a gelatin softgel shell and beeswax. That also means it is not vegetarian, and the label lists coconut as a tree-nut allergen. Sports Research says the product is third-party tested, made in a cGMP-compliant facility, gluten-free and IGEN Non-GMO tested, though it carries no NSF or USP seal.

buyers consistently credit it with less anxiety, better sleep and clearer focus, and like the easy-to-swallow softgel. The complaint that comes up most is occasional stomach upset, and one video reviewer noted the softgels are on the plump side. At $19.95 for 60 softgels, it costs more than bare-bones theanine capsules but remains reasonable for a branded ingredient.