Hair loss after bariatric surgery

Reading Time: 2 minutes

Many patients experience hair loss after weight loss surgery. In most cases this tends to be mild and short-lived, but is some cases the loss can be more severe and more persistent. So what causes hair loss after surgical weight loss treatments? First, some background about normal hair growth. 

Normal Hair Growth

Hair is made from a protein called keratin (the same as nail protein) which is produced in hair follicles in the outer layer of the skin. The average human head has around 100,000 hair follicles and as the follicles produce new hair cells, the old cells are pushed towards the surface and appear as long strings of dead keratin cells or what we recognise as normal hair. At any one time, about 90% of the hair on a person’s scalp is growing. 

There are three identifiable growth phases for human hair:

  • Anagenic: active hair growth which lasts between 2-6 years
  • Catagen – transitional, lasting 2-3 weeks
  • Telogen – resting phase lasting 2-3 months after which time the hair is shed and the growth cycle starts all over again

There are various causes of hair loss. The most common type seen after surgery is called telogen effluvium or hair shedding. It can have nutritional and non-nutritional causes such as severe infections, major surgery, low protein intake and anaesthesia. Anaesthesia can cause up to 30% more hair to move into the telogen phase, thereby accelerating hair loss. So both the stress of the surgery itself and the associated anaesthetic may contribute to hair loss. 

Then there are post-surgery nutritional factors which may contribute. There is much anecdotal evidence about this, but remarkably little real scientific evidence. The two most commonly cited micronutrient deficiencies associated with hair loss are iron and zinc.

Iron deficiency is common after weight loss surgery, especially after bypass. However, studies which have attempted to link iron deficiency and hair loss have produced inconsistent and sometimes conflicting results. Some of these discrepancies may be due to problems with the measurement of iron levels. 

Zinc deficiency has also been associated with hair loss, but as with iron, there is little evidence to support this. It is certainly true that both iron and zinc deficiency are common after bypass surgery, but it is not clear whether deficiency of either/both of these elements is the cause of hair loss.   Furthermore, no study has shown that supplementation of either of these (or any other) nutrients can prevent hair loss after surgery.

So what to do?  We suggest the following:

  • Make sure you are taking a multivitamin or iron supplement to provide a total daily intake of 50-100mg of elemental iron/day
  • Take some additional zinc – 10-20mg/day
  • Increase your protein intake to 60-70 grams/day


Perhaps the most important point to remember is that whilst hair loss after weight loss surgery is common, it is almost always temporary.  With the cessation of weight loss and the restoration of nutritional balance, hair re-growth is usual within 3-6 months. 

Picture of Martyn Berrett

Martyn Berrett

Martyn is the former MD of Healthier Weight. Throughout his tenure he observed many bariatric procedures and took part in several research projects so has a unique perspective on all things weight loss.

The Healthier Weight App

Conquer health goals through live support.


Get a FREE consultation by calling
0800 3134618 
Get a quote 
We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Your personal data will be used for the personalization of ads and cookies may be used for personalized and non-personalized advertising. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit “Cookie Settings” to provide a controlled consent.  Read our cookies policy here