Dr Amir Khan has addressed one of the most common concerns about weight loss jabs: hair loss. On an episode of his podcast No Appointment Necessary, the doctor explained that while hair loss can occur, it is not solely a side effect of the medication itself—it can happen to anyone losing weight rapidly.
Why does hair loss happen?
Speaking to co-host Cherry Healey, Dr Amir said: “Anyone who loses weight quickly, your body goes into a kind of famine crisis starvation mode.” Cherry added: “So your body says, ‘Oh my gosh, we're not eating enough, we've got malnutrition, we're in the middle of the desert, there's no food around. I'll make sure your heart is working but your hair can go.”
Dr Amir continued: “Your hair can go and that is true if you've lost weight quickly for any other reason. So whether it's illness, whether it's diet, whatever, if you lose weight rapidly, the same thing will happen.”
How to minimise the risk
Cherry asked if ensuring good nutrition while losing weight can help. She listed protein, leafy greens, vegetables, and legumes as beneficial foods. Dr Amir responded: “Yes, none of that is going to make you put on weight it's only going to make you leaner, stronger and healthier.” Cherry added: “I suppose it's that thing that you're changing your habits, so if you've eaten ultra-processed foods before or overeaten for your body, actually you're starting to reshape what food looks like.”
What does research show?
A recent study in the British Medical Journal found that using GLP-1 drugs was associated with a 37% higher risk of alopecia than SGLT-2 inhibitors and a 68% higher risk than DPP-4 inhibitors. Study authors noted: “Use of GLP-1 receptor agonists was associated with an increased risk of non-scarring alopecia in adults with type 2 diabetes. Although the absolute risk is low, awareness of this potential effect may help to inform treatment decisions.”
They added that case reports and FDA data have described hair loss after starting semaglutide (Wegovy, Ozempic) and tirzepatide (Mounjaro). The FDA is evaluating this safety signal. Hair loss may have psychosocial consequences, affecting self-esteem, quality of life, and treatment adherence.
Other side effects
According to the British Heart Foundation, around one in 10 people on GLP-1 inhibitors may experience digestive problems like nausea, diarrhoea, constipation, or stomach pain. Some also report tiredness, dizziness, hair loss, low blood sugar, or a fast heart rate. A rare but serious side effect is acute pancreatitis, causing sudden severe abdominal pain requiring immediate medical attention.
