L-Carnitine (the R-isomer) is the biologically active form recognized by the carnitine palmitoyltransferase shuttle system

the compositions comprise at least about 0.5 mg, at least about 0.75 mg, at least about 1 mg, at least about 1.5 mg, at least about 2 mg, at least about 3 mg, at least about 4 mg, at least about 5 mg, at least about 6 mg, at least about 7 mg, at least about 8 mg, at least about 9 mg, at least about 10 mg, at least about 11 mg, at least about 12 mg, at least about 13 mg, at least about 14 mg, at least about 15 mg, at least about 16 mg, at least about 17 mg, at least about 18 mg, at least about 19 mg, at least about 20 mg, at least about 21 mg, at least about 22 mg, at least about 23 mg, at least about 24 mg, at least about 25 mg, at least about 26 mg, at least about 27 mg, at least about 28 mg, at least about 29 mg, at least about 30 mg, at least about 31 mg, at least about 32 mg, at least about 33 mg, at least about 34 mg, at least about 35 mg, at least about 36 mg, at least about 37 mg, the compositions comprise at least about 2 mg of cofactor or precursor thereof (e.g., niacinamide) per milliliter of composition

It is required for proper muscle function, most notably, heart muscle
Physical inactivity independently contributes to erectile problems, whilst regular exercise has been shown to improve erectile function
How is a B12 injection administered and what is the dosage