HMB and Betaine: Two Testosterone-Adjacent Ingredients Almost No Product We’ve Reviewed Actually Uses
A 2023 review study concluded that most testosterone-boosting supplement ingredients don’t produce a meaningful hormonal change — with a couple of notable exceptions: HMB and betaine. Neither is a common headline ingredient in the products we’ve reviewed. Here’s what the actual research on each one shows.
HMB: What the Evidence Shows
HMB (β-hydroxy β-methylbutyrate) is a metabolite of the amino acid leucine, and it’s been studied for years for its role in reducing exercise-induced muscle damage and supporting lean mass in resistance-trained individuals.
Worth noting: this is a notably stronger, more recent, and more comprehensively pooled result than an earlier 2020 meta-analysis of just 7 studies, which found no overall testosterone effect and only a benefit in a specific exercise-type subgroup. The evidence base has genuinely strengthened as more trials have accumulated — a rare case where a later, larger analysis confirms rather than walks back an earlier finding.
Betaine: What the Evidence Shows
Betaine (trimethylglycine) is a compound found naturally in beets, spinach, and whole grains, more established in research for muscular strength and power than for hormones specifically.
An Important Population Caveat
This specific hormone-focused trial was conducted in 10 adolescent handball players (average age 16), not adult men. It’s a real, well-designed study, but the population is a meaningful mismatch for anyone reading this as an adult considering a testosterone supplement. Betaine’s benefit for strength and muscular endurance specifically is better established across multiple adult studies — the testosterone-specific finding above hasn’t yet been replicated in an adult population as far as we could find.
Doses Used in Research
| Ingredient | Dose in the Cited Research |
|---|---|
| HMB | Commonly around 3g/day across the pooled trials |
| Betaine | 2.5g/day in the hormone-specific trial; 1.25–6g/day across strength-focused studies |
A Gap in What We’ve Reviewed
Neither HMB nor betaine appears in the ingredient list of Testosil, TestoPrime, Testogen Ultimate, or Nugenix Total-T — the four testosterone support products we’ve reviewed. That’s not a criticism of any of them specifically; it just means if either of these two ingredients is your priority based on the evidence above, none of our current reviews are built around them. Both are also sold as standalone sports-nutrition supplements outside this specific product category.
FAQ
Are HMB and betaine legitimate testosterone boosters?
The evidence for HMB is genuinely solid at this point — a large, recent, well-conducted meta-analysis found a real effect. Betaine’s testosterone-specific evidence is real but currently limited to one small trial in adolescent athletes; its strength and endurance benefits are better established in adults.
Do any products we’ve reviewed contain these?
Not currently. None of the four testosterone support products we’ve reviewed list HMB or betaine among their ingredients.
Is HMB safe?
It’s been studied extensively in athletic populations without significant safety concerns at typical doses. As always, talk to a healthcare provider before starting any new supplement.
See the testosterone support products we have reviewed
Read Our Testosil ReviewLast reviewed: September 2026 · Read our full rating methodology · Clinical references: Bideshki et al., 2025 · Nobari et al., 2022.