Independent supplement ratingsUS and Canada · Updated weekly
A ratings desk for a category that has spent thirty years grading its own homework.
A ratings desk for a category that has spent thirty years grading its own homework.
Capsules · 60 count · 30 servings
Key actives at studied doses
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If you're going to buy a testosterone booster, this is the one we'd point you to — and read our honest take on the category first, because nothing here changes a normal man's hormones dramatically. Transparent Labs discloses every dose, third-party tests the product, and builds the formula around the few ingredients with any real human evidence: KSM-66 ashwagandha, tongkat ali, shilajit, boron and zinc. It tops the list not because it's magic, but because it's the honest, no-blend, no-hype option.
Full transparency: doses printed, no proprietary blend. KSM-66 ashwagandha and tongkat ali are the two actives with the most support, dosed in the studied range. Zinc, magnesium and vitamin D only do anything if you're deficient — useful insurance, not a testosterone switch. At about $1.67 a serving it isn't cheap, but you can see exactly what you're paying for.
For a man who wants the most evidence-backed, honestly-labelled option in a weak category — especially if you're stressed, sleep-deprived, or possibly low on zinc or vitamin D. If you expect a dramatic hormonal change, save your money; that isn't what any of these deliver.
Reviewed and fact-checked by the NFS editorial team · Last updated 12 Jul 2026