Where does the hair loss come from?
Heavy weight loss, few calories and little protein put the body under stress. Many hairs then enter the resting phase at the same time and fall out 2–4 months later. This is called telogen effluvium and is also known to happen after operations, infections or crash diets.
What helps?
- Enough protein: Hair is made of protein – a deficit shows up here early
- Get your bloods checked: ferritin (iron stores), zinc, vitamin D, thyroid
- Don’t lose weight too fast: avoid extreme deficits
- Patience: Regrowing hair usually takes 6–12 months
Be careful with high-dose biotin: without a deficiency it hardly helps and it can distort lab results, e.g. thyroid or cardiac values. Mention that you take it before blood tests.
When to see a doctor
- Round bald patches, itching or inflammation of the scalp
- Hair loss that hasn’t eased after 6 months
- Also severe tiredness, sensitivity to cold or a racing heart (thyroid, iron deficiency)
In an emergency: 112.
FAQ
Is hair loss from Mounjaro permanent?
As a rule, no. Hair usually grows back within 6–12 months once weight and diet stabilise.
Which blood values should I have checked for hair loss?
Often useful: ferritin, zinc, vitamin D and thyroid values. Your doctor decides.
Does biotin help with hair loss?
Only if you have a genuine deficiency, which is rare. In high doses, biotin can distort lab results.
Sources
This article does not replace medical advice. It gives no dosing recommendations. As of September 2026.