Table 4.
Creatine containing compounds that have no evidence of bioavailability, efficacy, and/or safety.
| Reference | Participants | Design | Duration | Dosing Protocol | Findings | Side Effects |
|---|---|---|---|---|---|---|
| Creatine Serum | ||||||
| Harris et al. [38] | 6 males | R | 1 oral dose with 7 day washout | Water Control, 5 mL CS (purportedly delivering 2.5 g CrM), 2.5 g CrM | CrM ↑ plasma Cr while CS had no effects and was similar to water. Analytic chemistry analysis showed < 10 mg of creatine and 90 mg creatinine in CS sample. | None reported. |
| Kreider et al. [27] | 40 males (18–30 years) |
RDBP | 5 days | 5 mL PLA, 5 mL of CS (recommended dose purportedly providing 2.5 g of CrM); 8 × 5 mL/day CS (purportedly providing 20 g/day of CrM); and 4 × 5 g doses of CrM (20 g/day) | CrM increased muscle creatine stores. Consumption of CS at recommended and 8× recommended levels had no effect. | None reported. |
| Creatyl-L-Leucine | ||||||
| Reddeman et al. [189] | Rats | Open Label | 90 days | Repeated-dose oral gavage toxicity study at doses of 1250, 2500, and 5000 mg/kg body weight per day. | There was no genotoxic activity observed in an in vivo mammalian micronucleus test at concentrations up to the limit dose of 2000 mg/kg body weight per day. The no observed adverse effect level from the 90-day study was determined to be 5000 mg/kg body weight per day, which was the highest dose tested for male and female rats. | None reported. |
| da Silva [221] | 24 rats | R | 7 days | Control diet, a diet containing 4.0 g/kg/day CrM, or a diet containing 6.56 g/kg/day CLL | CrM ↑ [creatine] in arterial plasma (+7-fold), portal vein plasma (+10-fold), muscle TCr (+1.63-fold from control, and +1.53-fold from CLL) while tending to increase brain creatine content compared to controls. CLL did not increase blood, muscle, and brain creatine content above rats fed a control diet with values lower than CrM. | None reported. |
| Creatinol-O-Phosphate | ||||||
| Nicaise et al. [233] | - | - | - | Intramuscular and intravenous injection | COP↑ handgrip performance. | None reported. |
R = randomized, p = placebo, DB = double-blind, SB = single blind; C = crossover, PLA = placebo, Cr = creatine; TCr = total creatine; CrM = creatine monohydrate, CS = creatine serum; CLL = creatyl-L-leucine; COP = creatinol-O-phosphate; ↑ = increase.