Ryan Reynolds is one of Hollywood's biggest stars.
The 42-year-old actor has starred in a string of big movies and is probably best known for the Deadpool franchise. He is married to the actress Blake Lively.
There has been a lot of speculation in the media over whether Reynolds has had a hair transplant.
Certainly his hair has thinned noticeably from his early years starring on TV and in films such as The Proposal.
In one TV interview he claimed that his hair became thicker through the use of shampoo. This is highly unlikely.
There is no a shampoo in the world that can permanently make your hair thicker.
The only long-term remedy for male pattern baldness is a hair transplant.
Most big stars who want to bolster their hairline opt for a FUE (follicular unit extraction) transplant.
FUE is the method chosen by 80% of the patients of Crown Clinic's hair transplant surgeon Asim Shahmalak.
Individual follicles are removed from the back and side of the scalp and then replanted in the balding areas.
The advantage of this method is that the scarring is minimal.
Most patients have red pin pricks where the donor hair is removed and replanted for a few weeks after the procedure which go away in the healing process.
Celebrity patients at Crown Clinic who have had FUE include the Coronation Street star Jack P Shepherd, who plays at David Platt in the soap, Homes Under the Hammer star Martin Roberts, the former footballer Didi Hamann and Googlebox star Chris Butland-Steed.
Jack P Shepherd had long-hair FUE with our surgeon Dr Shahmalak - so there was minimal disruption in the filming process of Coronation Street. He was able to retun to filming a little over two weeks after his procedure.
With long-hair FUE, the donor hair is harvested in a small patch of hair which is shaved at the back of the scalp. The hair above the shaved area falls over the shaved patch so the shaved area is not noticeable unless you lift the hair.
Around 20% of patients at Crown Clinic still opt for the more traditional form of hair transplantation, FUT (follicular unit transplantation), also known as strip surgery.
This is where a strip of skin is cut from the back or side of the scalp by Asim Shahmalak to harvest the donor hair. The folliciles are then replanted in the balding areas in the same way as FUE by Dr Shahmalak.
FUT is less labour intensive than FUE so it is less expensive and there is some evidence that more follicles survive when removed all in one go through the removal of the strip.
However, FUT does leave a noticeable scar on the scalp. It is not particularly noticeable if you like to wear your hair long but FUT is not suitable for men who like to shave their hair or wear it short.
The TV doctor Christian Jessen has had two FUT transplants with Dr Shahmalak.
So do we think that Ryan Reynolds has chosen either method?
It is impossible to say, but the actor is to be congratulated on great looking hair.