Benefits
Strength and muscle size with resistance training
In an 8-week trial of 40 young adults doing resistance training, creatine HCl (0.03 g per kg body weight a day) increased strength, arm and thigh muscle size and skeletal muscle mass more than placebo, matching two monohydrate regimens. In a smaller 8-week trial of 31 handball and softball athletes taking 5 g a day, no group differed from placebo on strength or body composition.
Sprint, jump and peak power performance
In a 4-week trial of 40 college soccer players doing repeated sprint training, 5 g a day of creatine HCl improved jump height, sprint time, an agility run and peak power more than placebo, with larger gains than monohydrate in some tests. Mean power and aerobic fitness did not differ between groups. This was a single small trial.
How it compares with creatine monohydrate
Two of three head-to-head trials found creatine HCl no better than monohydrate for strength, muscle or hormone changes. Because HCl is about 78% creatine by weight versus about 88% for monohydrate, an equal gram dose supplies slightly less creatine. A 2022 review found no evidence that HCl is absorbed better or that lower HCl doses work as well as standard monohydrate doses.
Water solubility and mixability
In a lab test, creatine HCl was about 38 times more soluble in water than monohydrate, so it mixes more easily. A later review noted the two were measured at very different acidity, and in a cell model of the gut lining, HCl passed through no better than monohydrate. Easier mixing has not been shown to improve absorption or results in people.
Mechanism of action
Raising muscle creatine stores
Creatine supplementation raises creatine levels in muscle, which may help explain improvements in high-intensity exercise performance and training adaptations. Creatine HCl is a simple salt expected to separate into creatine and hydrochloric acid, so the creatine it supplies is the same molecule as in monohydrate.
Solubility without a shown absorption advantage
Adding hydrochloric acid makes creatine far more water soluble, but creatine monohydrate is already well absorbed. A cell study found no difference in how well the two forms crossed a gut-like cell layer, and as of a 2022 review no published human study had measured muscle creatine retention with HCl.
Clinical trials
Randomized trial of four groups doing resistance training: creatine HCl 0.03 g/kg a day, monohydrate with a loading phase, monohydrate without loading (0.03 g/kg a day), or placebo (Eghbali et al. 2024, Physiol Res)
40 adults aged 18 to 25, 10 per group.
All three creatine groups increased strength (1RM), arm and thigh muscle cross-sectional area and skeletal muscle mass, and lowered body fat percentage more than placebo, with hormone changes (growth hormone, IGF-1, testosterone to cortisol ratio) also favoring creatine. Creatine HCl showed no benefit over monohydrate.
Randomized trial of 5 g a day of creatine monohydrate, creatine ethyl ester, creatine HCl or placebo during 4 weeks of repeated sprint training, three sessions a week; no funding reported (Duan et al. 2026, J Int Soc Sports Nutr)
40 male collegiate soccer players.
All groups improved with training. The creatine groups improved physical performance, peak power and fatigue index more than placebo, and the ethyl ester and HCl groups gained more than monohydrate in jump, sprint, agility and peak power. Mean power and VO2max did not differ between groups.
Triple-blind, placebo-controlled randomized trial of 5 g a day of creatine monohydrate, creatine HCl or maltodextrin for 8 weeks, published as a conference abstract and not indexed in PubMed (Londoño-Velásquez et al. 2025, J Int Soc Sports Nutr)
31 male and female handball and softball players aged 18 to 28.
No measure of strength, jump performance or body composition differed between the three groups, including versus placebo. Within each creatine group, jump performance and fat-free mass improved from baseline, with similar small effects for both forms. The authors concluded that claims of HCl superiority are unfounded. Two authors serve on a creatine maker's advisory board.