Jump to: Why might Mounjaro cause hair loss in some people? | How can you avoid hair loss on Mounjaro? | Can hair loss be reversed? | Take home message
Mounjaro can cause hair loss (alopecia) or hair thinning. However, data from randomised controlled trials suggest this side effect is rare and occurs in around 5% of people taking the medication.
Rapid weight loss can also lead to hair loss (alopecia) or hair thinning, possibly due to very low-calorie intake and inadequate intake of essential nutrients like iron and zinc.
So, it’s unclear whether the hair loss on Mounjaro is due to the drug itself (for example, whether it directly affects the body’s ability to grow and maintain hair follicles) or as an indirect effect due to the weight loss observed when on the medication.
Most people taking Mounjaro don’t experience hair loss, but there are ways to avoid it during a weight loss journey, like ensuring you eat a diet based on whole foods with enough protein.
On Second Nature’s Mounjaro weight-loss programme, our health coaches are online five days a week to offer guidance on nutrition and habits to avoid and manage side effects while on the medication.
Why might Mounjaro cause hair loss in some people?
Data from randomised controlled trials shows that Mounjaro supports average weight loss of up to 26% after two years. It’s likely that within this average, some participants lost weight faster.
Rapid weight loss (beyond the recommended 1-2lbs per week) has been shown to increase the risk of hair loss compared to losing weight slower.
One study compared two weight loss approaches in women and its impact on lean mass (muscle and bone) retention:
- Severe caloric restriction (65-75% below energy balance)
- Moderate caloric restriction (25-35% below energy balance)
The results showed that eight adverse events occurred in the severe group compared to two in the moderate group.
Two of the adverse events in the severe group were hair loss, while no one in the moderate group reported hair loss.
Similarly, a systematic review and meta-analysis (a study summarising the results of multiple studies on one topic) showed that hair loss was a common side effect after patients had bariatric surgery, as weight loss in the months after surgery is significant.
From a nutrition perspective, there are three potential reasons why rapid weight loss may lead to hair loss or thinning:
- Very low-calorie intake can restrict the amount of energy available to grow and maintain hair follicles
- Low-calorie intake inherently leads to low protein intake. Protein is an essential nutrient for hair growth and maintenance.
- Low intake of essential nutrients, like zinc, iron, and B vitamins, can lead to hair loss or thinning
While the medication has potential effects on hair growth, this is largely speculative at this stage as more research is needed.
The most likely cause of hair loss in Mounjaro is the indirect effect of the medication on weight loss.
How can you avoid hair loss on Mounjaro?
As highlighted above, the three main nutritional reasons for rapid weight loss and Mounjaro can cause hair loss are insufficient calories, protein, and essential nutrients like zinc, iron, and B vitamins.
So, let’s look at these three factors in more detail.
1 – Eating enough calories
A common misconception about weight loss is that ‘less is more.’ In fact, the most sustainable approach to weight loss, particularly to avoid hair loss, is to avoid restricting calories too much.
Generally, this means achieving a calorie deficit of around 10-25%. We don’t recommend counting calories on our Mounjaro weight-loss programme as there are more sustainable approaches to managing calorie intake.
At Second Nature, we recommend the following strategies to manage calorie intake:
- Eat three meals a day based on whole foods
- Ensure each meal contains at least 25% protein, 25% complex carbohydrates, 50% vegetables (or servings of fruit for breakfast), and a source of fat
- Eat until you’re comfortably full
- If you’re losing weight too quickly, add in protein-rich snacks like tinned fish on rye crackers or cured meats and cheese
2 – Eat enough protein
The best approach to protein intake is to make protein the priority for each meal. So, take a ‘protein-first’ approach to your meals.
Prioritising protein means selecting your protein source for the meal and basing the meal around it. For example, you could choose chicken thigh as the protein source and research a good recipe.
Another example is basing your breakfast on yoghurt or eggs and finding suitable sources of carbohydrates, fat, and fibre to accompany them.
We recommend ensuring each meal contains at least 25% protein or a protein source the size of an open hand.
3 – Consume essential nutrients like iron, zinc, and B vitamins
Rather than aiming to consume more foods rich in these ingredients, it’s easier to focus on a broader approach to simplify things.
We recommend consuming a wide variety of whole foods to ensure you’re getting sufficient essential vitamins and minerals.
Here are some tips:
- Eat the rainbow: Eat a wide variety of fruits and vegetables
- Mix up your protein source: Rotate through different protein sources each week
- Prioritise whole foods over ultra-processed foods
- Include other plant foods like nuts, beans, and pulses
Can hair loss on Mounjaro be reversed?
Research on recovering hair loss after being on Mounjaro and losing weight is limited.
However, it’s believed that hair loss after losing weight can be reversed following the re-introduction of protein, essential nutrients, and calories.
This process of recovering hair growth may take many months as the body builds up its stores of the essential nutrients required for hair growth.
If you’re experiencing more extreme forms of hair loss, like alopecia or telogen effluvium (TE), we’d recommend speaking with your doctor as these may have a different cause, such as psychological stress.
Take home message
Hair loss on Mounjaro is a rare side effect of the medication, and the most likely cause is rapid weight loss induced by very low calorie and protein intake.
This side effect occurs in less than 6% of people on Mounjaro, and most people won’t experience this issue.
If you’re currently taking Mounjaro, you should report all side effects to your prescribing pharmacist so that they can discuss potential solutions to help manage them.
On Second Nature, our team of registered nutritionists and dietitians are online five days a week to offer lifestyle advice to help manage life on Mounjaro and maximise weight loss results.
Second Nature’s medication programmes
Second Nature has two medication-supported programmes: a Wegovy weight-loss programme and a Mounjaro weight-loss programme.
Why should you choose Second Nature over other medication providers if you’ve decided to try Mounjaro or Wegovy (assuming you’re eligible)?
For peace of mind.
Second Nature has worked with the NHS for over 6 years, providing weight-loss programmes across the UK.
While our Wegovy and Mounjaro weight-loss programmes are private and not currently used by the NHS, we’ve built the programmes focusing on scientific evidence, patient safety, and data security.
We hope that our 6+ years of working with the NHS and building a track record of effective weight-loss results will give you peace of mind to give us a try.
