Our reviews page shows three reader-submitted reviews, each labelled as a personal opinion. They are worth reading, but they are not evidence in the scientific sense.
A scientific sample needs enough people, chosen without bias, with a measured starting point and ideally a comparison group. Reader reviews are self-selected, unverified and have no baseline. Three entries, all rated five stars, tell you what three people chose to write, nothing about how a typical buyer will feel.
Expectation also plays a part. Someone who has paid for a supplement and hopes it works may notice improvements that would have happened anyway, from better sleep, a lighter week or simply paying attention.
Look for specifics rather than stars: how long the person took it, what else changed, what they actually noticed, and whether they mention any downside. One reviewer says afternoons felt less flat after about two months, which at least matches the brand's own cumulative-timeline wording. Treat that as an anecdote, and run your own simple log instead.