Maca's effect
I, too, use maca and have found it to have little effect on erections, but it does seem to intensify the sensitivity or pleasure aspect, possibly explained by the following……………
A quote from a web site I found when researching:
It may well be that maca’s beneficial effects for sexual function and fertility can be explained simply by its high concentration of proteins and vital nutrients. Dried maca root contains about 10% protein—mostly derived from amino acids. Amino acids (the building blocks of proteins) are required in the diet to drive many cellular functions in the body—including sexual and fertility functions. Amino acids are required to manufacture neurotransmitters such as dopamine and noradrenaline. These substances transmit signals in the nervous system and play a major role in the process of sexual arousal and physical performance during sex. The main amino acids that these neurotransmitters require include phenylalanine, tyrosine, and histidine (all three of which are found in good supply in maca).