Smoking has specific, well-documented effects on wound healing and blood supply that make it a significant risk factor in hair transplant surgery. Understanding the mechanism helps patients appreciate why the instruction to stop smoking is medical rather than moralising.
Nicotine causes vasoconstriction — narrowing of blood vessels. This reduces blood flow to peripheral tissues including the scalp. Transplanted grafts depend on establishing new blood vessel connections in the recipient area in the days following implantation — a process called neovascularisation. Reduced blood supply during this critical period impairs neovascularisation and reduces graft survival rates.
Carbon monoxide from cigarette smoke reduces the oxygen-carrying capacity of haemoglobin. The already-challenged blood supply to newly implanted grafts carries less oxygen when smokers continue smoking post-operatively, compounding the vasoconstriction effect.
The evidence for smoking’s effect on wound healing is robust across all surgical contexts. Smokers have significantly higher rates of wound complications, infection, and poor healing than non-smokers. In the specific context of hair transplantation, studies have shown meaningfully lower graft survival rates in smokers compared to non-smokers even when all other surgical factors are held constant.
The standard recommendation is to stop smoking at least two weeks before the procedure and for at least two weeks after. Four weeks either side is better. Nicotine replacement therapy — patches, gum — also causes vasoconstriction (the nicotine is the active compound, not the smoke specifically) and should similarly be stopped or significantly reduced.
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