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Mounjaro & Wegovy Hair Loss: Causes and Advice

Weight Loss Injections and Hair Loss: Causes, Prevention and Recovery

Prescription weight loss injections have changed the management of obesity and related metabolic conditions.

Medicines such as Mounjaro (tirzepatide) and Wegovy (semaglutide) can produce clinically significant weight reduction when prescribed appropriately.

However, some patients report increased hair shedding during treatment.

Understandably, this can be distressing, particularly when someone is otherwise experiencing positive changes in their health.

The important question is whether the medication itself, the associated weight reduction or another underlying factor is contributing to the problem.

Can Mounjaro and Wegovy cause hair loss?

Hair loss has been reported during treatment with medicines used for weight management, including tirzepatide and semaglutide.

However, several mechanisms may contribute.

Significant weight reduction, reduced energy intake, changes in dietary protein consumption and nutritional deficiencies are all relevant considerations.

A common explanation for diffuse shedding following major physiological change is telogen effluvium.

Not every patient receiving these medicines will experience hair loss, and the cause should not be assumed without assessment.

What is telogen effluvium?

Telogen effluvium is a form of diffuse, non-scarring hair shedding.

Normally, most scalp hair follicles are in the active growth phase, while a smaller proportion are resting.

Following a significant physiological stressor, more follicles may transition into the resting phase.

The resulting shedding commonly becomes noticeable around two to three months after the triggering event.

Patients often describe finding more hair in the shower, on their hairbrush or when washing their hair.

The shedding may affect the entire scalp rather than producing a clearly defined bald patch.

Why can rapid weight loss trigger shedding?

Hair production requires energy, protein and essential micronutrients.

During significant calorie restriction, the body adapts to reduced nutritional availability.

Although the precise mechanisms are complex, rapid weight reduction and inadequate protein intake are recognised potential triggers for telogen effluvium.

The degree of risk varies between individuals.

A person losing weight gradually while maintaining adequate nutrition may have a different experience from someone struggling to eat sufficient food because of persistent nausea or early satiety.

How much protein should you eat?

Protein requirements vary according to age, body weight, physical activity, kidney function and overall health.

For healthy adults, the UK reference nutrient intake is approximately 0.75 g of protein per kilogram of body weight per day.

During intentional weight loss, some individuals may benefit from higher protein intake to support lean tissue preservation, particularly when combined with resistance exercise.

A commonly considered range in appropriate adults is around 1.0–1.2 g/kg/day, with higher targets sometimes used following individual assessment.

For example, a person weighing 75 kg might be advised to aim for approximately 75–90 g of protein daily, depending on their circumstances.

This is not a universal prescription. People with chronic kidney disease, particularly those receiving specialist renal care, require individualised dietary guidance.

Which nutritional deficiencies should be considered?

Several deficiencies may be relevant when investigating hair shedding.

Iron deficiency

Iron deficiency is particularly important where dietary intake is reduced or there is a history of heavy menstrual bleeding.

A full blood count and ferritin may be appropriate depending on the clinical presentation.

Vitamin B12 and folate

Inadequate intake or malabsorption may contribute to deficiency, particularly in people following restrictive diets.

Vitamin D

Vitamin D status may warrant consideration where there are relevant risk factors, although routine testing is not necessary for every person experiencing hair loss.

Zinc

Zinc deficiency may affect hair health, but excessive zinc supplementation can also cause problems, including copper deficiency.

Supplementation should therefore be guided by clinical need rather than taken indiscriminately.

Can hair supplements prevent shedding?

There is currently insufficient evidence that taking a general hair supplement reliably prevents telogen effluvium associated with weight loss medication.

Products such as TrichoRx24 may be discussed as part of a wider nutritional review, but they should not replace adequate dietary intake or the correction of identified deficiencies.

If someone is unable to consume enough protein or calories, addressing that problem is more important than adding multiple supplements.

What about Elcella?

Elcella is a non-prescription food supplement developed around appetite regulation and gut hormone signalling.

It is not equivalent to Mounjaro or Wegovy and has not been established as a treatment for medication-associated hair loss.

Anyone considering Elcella while using prescription weight management medication should obtain professional advice regarding suitability.

How can hair loss be assessed?

At GrowBack, we take a detailed history of the patient’s hair loss, including its onset, pattern, progression and possible triggers.

Where appropriate, assessment may include:

• Examination of the scalp and hair.
• HairMetrix imaging to document selected hair and scalp measurements.
• Review of medication and weight changes.
• Assessment of dietary intake and possible nutritional deficiencies.
• Relevant laboratory investigations.
• Consideration of genetic or hormonal hair loss occurring alongside telogen effluvium.

This distinction matters because telogen effluvium and androgenetic alopecia can coexist.

A person may notice diffuse shedding following weight reduction while also having an underlying tendency towards progressive pattern hair loss.

Will the hair grow back?

Telogen effluvium is often reversible once the triggering factor has resolved.

Shedding may settle over several months, although visible recovery of hair volume can take considerably longer.

The outcome depends on the underlying cause, the duration of shedding and whether other hair loss conditions are present.

Persistent shedding, patchy hair loss, scalp inflammation or progressive thinning warrants further assessment.

Should you stop your weight loss injections?

Do not stop prescribed medication solely because of hair shedding without discussing the situation with your prescribing clinician.

The benefits of treatment, the rate of weight reduction, nutritional intake and possible adverse effects should be reviewed together.

For some patients, adjustments to dietary intake or the weight management plan may be appropriate.

Our approach at GrowBack

We understand that hair loss can undermine confidence at a time when patients are making significant improvements to their metabolic health.

Our aim is to identify the likely cause, assess nutritional and follicular health, and develop a personalised management plan.

If you are experiencing hair shedding while taking Mounjaro, Wegovy or another weight management treatment, arrange a specialist consultation through www.GrowBack.co.uk.

References

Guo, E.L. and Katta, R. (2017) ‘Diet and hair loss: effects of nutrient deficiency and supplement use’, Dermatology Practical & Conceptual, 7(1), pp. 1–10. https://doi.org/10.5826/dpc.0701a01

Drake, L. et al. (2023) ‘Evaluation of the safety and effectiveness of nutritional supplements for treating hair loss: a systematic review’, JAMA Dermatology, 159(1), pp. 79–86. https://pubmed.ncbi.nlm.nih.gov/36449274/

National Institute for Health and Care Excellence (n.d.) British National Formulary: Semaglutide and tirzepatide. Available at: https://bnf.nice.org.uk/