Two carnosine gels. One trial between them.

What is actually in each bottle

Both are 100 ml. LactiGo’s menthol version is registered with the FDA as an over-the-counter topical analgesic. That is what the 1.25% menthol buys it. Note which ingredient the filing names as active: menthol, not carnosine. Carnosport makes no such filing and lists carnosine as its only active.

The concentration question, which Carnosport wins

LactiGo lists L-carnosine in its ingredients and nowhere says how much. Carnosport prints 4% on the product page. The whole premise here is getting one dipeptide through skin. How much sits in the tube is not a detail. It is the number that decides whether the thing could work at all, and only one of the two firms publishes it.

We sell LactiGo and this still goes in Carnosport’s column. Nobody outside the manufacturer knows what concentration LactiGo is, which means nobody can compare the two formulas on the one variable that should matter most.

The evidence question, which LactiGo wins outright

Four trials of topical carnosine exist. All four used LactiGo, and one of those four found no effect on anything it measured — that one is on our evidence page at the same size as the others. Carnosport has been tested zero times.

Carnosport’s science page cites Beaven et al. 2025 — the triple-blind rugby sevens trial. That trial applied LactiGo. The rest of the page rests on general carnosine and beta-alanine physiology: Harris 1974 on muscle carnosine, Hobson 2012 on oral beta-alanine, Baguet 2010 on rowing. Good papers, none of them about a gel, and none of them about their gel.

Carnosport without menthol is the cleaner experiment

The long-running objection to carnosine gel is that menthol does the work. A carnosine gel with no menthol in it is the obvious way to settle that, and Carnosport is exactly that product. It is genuinely the more interesting formula to test.

Two things complicate it. First, LactiGo already sells a menthol-free version. You do not have to switch brands to run that test. Second, the 2025 trial already ran the controlled version of it. The placebo was ultrasound gel matched to 1.25% menthol. Both bottles tingled the same. Peak power was still 8–12% higher on the carnosine arm. The menthol question has an answer, and it did not need a second product.

• Topical menthol on its own is worth a small gain — sixteen studies, 191 participants, g = 0.27 — mostly in aerobic endurance, mostly through perceived cooling.
• That is a different variable from the peak power the carnosine arm moved. It is why a menthol-matched placebo changed the argument.
• None of this has been demonstrated for Carnosport’s formula, because nobody has run it.

Which one to buy

• You want the product the trials were run on, and batch testing you can check against Informed Sport: LactiGo. That is also the one we sell, and you should weigh this page accordingly.
• You are drug tested and want certification rather than a claim: LactiGo. Informed Sport screens every batch; "clean-sport approved" is a statement, not a programme.
• You react badly to menthol or cannot use a scented product at training: either the menthol-free LactiGo or Carnosport. Only one of those two has any trial behind the brand.
• You refuse to buy a supplement that will not print its concentration: Carnosport, and the reasoning is sound.

What neither company can tell you is whether a 4% stated concentration in a Danish carbomer gel behaves like an unstated concentration in a magnesium-and-menthol carrier. Absorption depends on the carrier as much as the molecule, and the only absorption data anyone has is from horses.