This has been discussed at lengths in the past, and the general opinion seems to be that there is no evidence linking masturbation to the success of transplant. I think some advise 'no fap' for a while because of the rush of blood to the scalp may cause swelling shortly after procedure etc...
The 'loss of protein' view make sense in theory but also seems to have little influence on growth from what I read.
The influence on the hormonal level and DHT had been discussed as well, but also inconclusive. At early stages of growth, there are so many variables to stress you out, so if this is adding to it, just refrain for a peace of mind.
