Pilot evidence that topically applied triiodothyronine (T3) can stimulate hair growth in human scalp skin

Despite its limitations, our pilot study presents the first proof of principle that topical T3 can indeed promote hair growth (i.e., prolong anagen) and can stimulate the intrafollicular production of a potent hair growth factor (FGF7/KGF) in intact human scalp skin ex vivo, i.e. directly in the human target organ. We also show that the simple, clinically relevant vehicle we have developed and tested here facilitates topical HF-targeting THs delivery through an intact epidermal barrier.