Hair transplant risks and side effects

How risky is a hair transplant?

A hair transplant is done under local anaesthetic and serious complications are uncommon. Most problems people run into are either expected short-term effects, like swelling and tenderness, or disappointing results, like poor growth, a hairline that looks wrong or a thinned donor area. Those second kinds of problems are often the ones that matter most over the long term.

A 2025 systematic review pooled observational studies covering 2,353 patients and found that 18.8% reported a complication of some kind, with pain, swelling and discomfort the most common. Rates vary a lot between studies, because each one defines and records complications differently.

Your doctor should explain the risks that apply to you before you agree to surgery. Under the Medical Board of Australia's guidelines for cosmetic procedures, the practitioner has to assess you, discuss risks and costs and get your informed consent.

Risks at a glance

Swelling, bleeding and infection

Swelling of the forehead and around the eyes is the most common short-term effect. One retrospective study found it in 42.47% of patients, mostly two to six days after surgery. It looks worse than it is and settles without treatment. Sleeping with your head raised in the first nights can help, as our recovery guide explains.

Bleeding is usually minor oozing. Steady pressure with clean gauze for 10 to 15 minutes normally stops it. Tell your doctor beforehand about any blood thinning medication, supplements or bleeding problems.

Infection is uncommon, and serious infection is reported at under 1%. The risk is higher with poor hygiene, heavy crusting and conditions such as diabetes. Signs include spreading redness, heat, pus, fever and pain that gets worse rather than better.

Numbness and folliculitis

Numbness or tingling in the donor or recipient area is common in the early weeks and usually improves as small nerves recover. It was reported in 10.96% of patients in one study. Persistent numbness or pain is less common, and is linked to deep incisions that damage larger nerves in the back and sides of the scalp.

Folliculitis means inflamed hair follicles that look like small pimples. It can appear weeks or months after surgery as new hairs push through the skin. It was the most common complication in one surgeon's series of 2,896 patients, where it lasted from three weeks to three months. Most cases are mild. Infected or persistent cases are treated by the clinic.

Poor growth and unnatural results

Not every graft survives. Poor growth can come from rough handling or drying out of grafts during surgery, grafts placed too deep or too shallow, heavy smoking, diabetes and sun damage to the scalp. You cannot judge growth properly until at least 12 months, as the results timeline explains.

An unnatural result usually comes down to planning and design. Common problems include a hairline set too low or too straight, temples that are filled in bluntly, hairs placed at the wrong angle, and grafts that look like clumps. A hairline that suits you at 25 may look out of place at 50, which is why an age-appropriate design matters. Our hairline transplant page covers this in more detail, and repair work is possible but harder than getting it right the first time.

Scarring and overharvesting

Every method leaves some scarring in the donor area. FUT leaves a linear scar across the back of the head, which can stretch or widen, particularly if too wide a strip is taken or the closure is under tension. FUE almost always leaves small round scars, which can show as pale dots if you cut your hair very short. Keloid or raised scars are rare. See FUE vs FUT for the trade-offs.

Overharvesting happens when too many follicles are taken from the donor area, leaving it visibly thin or patchy. The International Society of Hair Restoration Surgery's FUE guidelines warn against high-density extraction in a single session and against further scalp harvesting once visible donor thinning has occurred. Overharvesting is permanent and uses up hair you may need later.

Shock loss

Some people lose some of their existing hair around the transplanted area, or in the donor area, in the weeks after surgery. This is called shock loss. It is usually temporary, with recovery over three to four months, and women and people with a lot of already thinning hair are at higher risk.

How to reduce your risk

• Check the doctor on the Ahpra public register, and ask who will do each part of the procedure. Our guide on how to choose a clinic covers what else to check.
• Give a full medical history, including diabetes, smoking, bleeding problems and every medication and supplement you take.
• Ask for a plan that allows for future hair loss, not just your hair loss today, and ask how many grafts will be taken and from where.
• Be cautious with packages that promise very high graft counts at a low price, whether in Australia or overseas.
• Stop smoking around the procedure if you can, and follow the aftercare instructions closely.
• Know who to call after hours, and do not wait if you see signs of infection.