There is one healing peptide that a lot of body builders are using and a lot of them are reporting hair growth and thickening, just by when they inject is subcutaneously once a week. It's TB500, or by its scientific name Thymosin-β. Thymosin has been associated with stimulating hair growth factors, and since it is involved in healing, it's not surprising. If these users are getting results by injecting it into their skin, which dilutes it across the entire body, just imagine if it were applied to the scalp after dermarolling. There's a 2015 study that linked Thymosin Beta with hair growth in mice... I can't link the study because my account is new but you can find it with its PMID: 26083021. It's called "Thymosin Beta-4 Induces Mouse Hair Growth". Unlike PTD-DMB, Thymosin Beta is available for purchase online right now, and it's really not that expensive at all. As of right now though I am not aware of anyone applying it to their head. I think someone mentioned the idea on a body building forum, but most people seem to be more interest in its benefits to bodybuilding.
Peptides are amazing because they're being utilized directly by the cell. The unfortunate thing is that PTD-DMB thread on Reddit didn't really seem to spark that much attention. Most of the peptides being discussed there are performance enhancing ones. Nevertheless there is interest. I think the big limiting factor now is just that not many people know about it.
good sh*t thanks man, just from a quick google search there seems to be some interesting stuff on thymosin b. surprised this avenue hasnt been explored yet as it seems it directly stimulates hair follicle stem cells to activate. hopefully someone here or on reddit contacts gang luo as he seemed fully onboard for making ptd dbm and has made stuff for a couple guys in the other thread that were tested to be pure