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 · 120 count · 30 servings
DAA 2,300mg / ~2,000–3,000mg studied
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A transparent, well-dosed label built on a shaky headline ingredient. TestoFuel discloses its doses (good) and centres the formula on D-aspartic acid at 2,300 mg — a dose that matches early research, except that later, better-controlled studies mostly failed to reproduce any testosterone benefit from it. The rest — vitamin D, zinc, magnesium, fenugreek, oyster extract — is sensible but modest. At $2.16 a serving, you're paying a premium for a formula whose star player the evidence has largely walked back.
Doses are printed and there's no blend to hide behind — that's the good part. The problem is what the doses are of: D-aspartic acid is the biggest line, and the weight of evidence now says it doesn't reliably raise testosterone in healthy, trained men. The supporting cast mostly helps only if you're deficient.
Fine if you specifically want a transparent label and don't mind paying up, but Transparent Labs gives you a better-evidenced mix for less. Skip it if D-aspartic acid was the reason you were interested.
Reviewed and fact-checked by the NFS editorial team · Last updated 12 Jul 2026