Hair Loss Following Bariatric Surgery

It is common to notice increased hair loss in the months after bariatric surgery. The good news is this is only a short-term side effect and your hair will grow back.  

Why does it happen?

The stress of surgery and rapid weight loss pushes a larger-than-normal share of hair follicles from their growing phase into a resting phase. About 2–3 months later, those resting hairs shed together, so the loss is diffuse (all over the scalp) rather than in patches.

Not eating enough protein, or being low in zinc, iron or folate, can make the hair loss worse or more prolonged.

How common is it and when?

•   Common: roughly half of patients (about 47–57%) notice excess hair loss in the first year following surgery, with it being most common in younger women.  

•   Timing: hair loss typically begins at around 3 months and is most noticeable between months 3 and 6.

•   Recovery: it is self-limiting – regrowth typically follows once weight stabilises and nutrition is on track.

•   Procedure: gastric bypass carries a somewhat higher risk than sleeve gastrectomy.

What helps

•   Meet your protein target. Aim for a minimum of 60g protein/day (or the amount your Dietitian sets for you). Protein is the building block of hair.

•   Take your prescribed supplements every day. A complete bariatric multivitamin teamed with a bariatric Calcium/Vitamin D, along with any other supplements your Dietitian or Surgeon has prescribed.

•   Keep your follow-up blood tests. These check the levels of nutrients mentioned above which can worsen or prolong the hair loss, so any deficiency can be corrected early to minimise further loss.

•   Avoid self-prescribing extra supplements. Popular supplements such as biotin and vitamin E are not shown to help and too much zinc can cause a copper deficiency. Always check with your team first.

•   Be gentle with your hair. Avoid tight styles and harsh treatments while hair loss settles.

When to speak with your team

Contact us if hair loss is in distinct patches rather than diffuse, if it continues beyond 12 months or if you are struggling to meet your protein and supplement goals. These may point to a treatable nutrient deficiency or another cause worth reviewing.

References

Zhang W, et al. Hair Loss After Metabolic and Bariatric Surgery: a Systematic Review and Meta-analysis. Obes Surg. 2021;31(6):2649–2659.  •  Updated systematic review and meta-analysis, Obes Surg. 2025 (41 studies, n=7044).  •  Cohen-Kurzrock RA, Cohen PR. Bariatric Surgery-Induced Telogen Effluvium (Bar SITE). Cureus. 2021;13(4):e14617.  •  ASMBS Integrated Health Nutritional Guidelines (micronutrients), 2016 update.

This handout is general information and does not replace individual advice from your Dietitian, Surgeon or GP.