What will happen if I had sex and drink alcohol after hair implant?

I'm not sure how long your doctor asked you to refrain from sex and alcohol, but I encourage you to comply. Sex is simply for the cardio, we want to keep your heart rate down to ensure you keep all yo grafts. Alcohol thins your blood. We want to everything possible to minimize bleeding post procedure. Typically I encourage patients to avoid sex and alcohol for 48 hours.

Greetings,We advise to avoid sexual activity for first week after hair transplantation.  The rationale is to avoid increasing blood pressure.  There are no studies supporting this however.  
Best 
Anil Shah MD

Perhaps you should ask your doctor who said not to have sex and drink alcohol after your surgery.  Each doctor have their own reasons.

The reasoning behind the alcohol cessation just after a transplant (1-2 days at our clinic) is for one main reason in my opinion. It is excess bleeding that could occur from the alcohol thinning the blood. These freshly planted grafts can become loosened the first 24 to 48 hours. An additional problem we witnessed once was a guy went to a bar and consumed alcohol heavily, got into a fight and bumped his head the night of his transplant. That was disastrous.  In terms of sexual activity the first few days post op, it would not be advisable. Sexual activity will or can cause excessive bleeding because of the heart rate and blood pressure rising from the activity. So across most clinics they usually advise to not participate in these activities for a few days.

Once the transplant is secure (3 days) you should be able to do almost anything. I will not comment on smoking and drinking as that is not my role with you