Introduction

One treatment that has revolutionised the management of type 2 diabetes and obesity is ​Glucagon-like peptide-1 receptor agonists (GLP-1 RAs), such as Semaglutide (Ozempic, Wegovy) and Tripeptide (Mounjaro, Zepbound). However, there have been growing concerns about possible adverse effects, such as hair loss.

Nonetheless, there is an ongoing controversy around this potential side effect, and its underlying mechanisms are not fully understood. This article will summarise what has been done and what remains to be done to clarify the extent of this association and develop strategies for prevention and management.

Understanding GLP-1 receptor agonists

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs are a class of medications primarily used to manage type 2 diabetes mellitus and obesity. They function by mimicking the action of the hormone GLP-1, which is naturally produced by the gastrointestinal tract in response to food intake.

By binding to the GLP-1 receptor, these medications enhance insulin secretion, suppress glucagon release to reduce hepatic glucose production, delay stomach emptying, and promote feelings of fullness. These combined actions result in improved glucose control and notable weight loss, making GLP-1 RAs highly effective for managing the aforementioned conditions.

Several GLP-1 RAs have been used in clinical practice, including Semaglutide (Ozempic, Wegovy), Liraglutide (Victoza, Saxenda), Dulaglutide (Trulicity), and Exenatide (Byetta, Bydureon). These medications are typically administered via subcutaneous injection, however, oral formulations such as Semaglutide (Rybelsus) have recently emerged, further enhancing patient convenience and compliance.

This medication, like many others, is not without side effects; the most frequently reported adverse reactions are gastrointestinal, such as nausea, vomiting, diarrhoea, constipation, and abdominal discomfort. Additionally, although rare, these medications carry potential risks such as pancreatitis. Besides, some emerging studies have listed hair loss as an additional side effect.¹

Hair loss 

Alopecia is the medical term for hair loss. It is a common condition that can affect individuals of all ages, genders, and backgrounds. It is defined as excessive hair loss beyond the normal that can lead to visible thinning, patchiness, or even complete baldness.

There are several types of hair loss, and there are also different underlying causes. The mentioned treatments, such as GLP-1 receptor agonists, have a defined interaction with hair loss.. A critical relationship must be identified, as hair loss often coincides with other related factors, like rapid weight loss or nutritional imbalances, which are common during treatment and can independently contribute to hair loss.²

Are GLP-1s causing hair loss?

There is an intriguing relationship between hair loss and GLP-1 RAs. A recent study has demonstrated that GLP1-RAs were the most reported class of medications with hair loss, and Semaglutide, Liraglutide, and Dulaglutide were the three leading medications compared with other medicines used in diabetes. This occurred through mechanisms like telogen effluvium (TE) due to rapid weight loss. Conversely, some studies suggest the potential benefits of GLP-1 RAs, such as increased insulin sensitivity and enhanced scalp blood circulation, could theoretically support hair health.

Why might weight loss lead to hair loss?

Weight loss, whether natural or induced by medication, can be one of the causes of hair loss. Highly sensitive changes in nutritional status, crash diets or appetite suppressors like GLP-1 RAs might unintentionally lower the intake of vital nutrients. Hair thinning and loss have been linked to iron, zinc, biotin, essential fatty acids, and protein deficits. Furthermore i hormonal changes could be involved, which is linked to notable weight loss. Weight changes can affect thyroid hormones, insulin, and sex hormones, including estrogen and testosterone,  all of which can affect the hair growth cycle. Adding to that, emotional stress that often accompanies major lifestyle changes, even positive ones like successful weight loss, may have an effect. Psychological stress is a well-known trigger of TE and can compound the effects of nutritional and hormonal factors. 

What can you do if you are losing hair?

Identifying the underlying cause of hair loss is crucial for effective treatment. If GLP-1 RAs are suspected, with sufficient evidence to be contributing to the hair loss, adjusting the medication dosage or discussing lifestyle modifications is advised. However, it is essential to complete all necessary tests and closely follow your doctor’s advice to ensure an accurate diagnosis and appropriate management. If a nutritional deficiency is identified as the cause, appropriate supplementation may be recommended. ³

Summary

The possible connection between hair loss and GLP-1 receptor agonists (GLP-1 RAs), drugs extensively used for diabetes control and weight loss. It provides an overview of GLP-1 RAs, their mechanism of action, and the multifactorial nature of hair loss, including a potential link with rapid weight loss and nutritional deficiencies.

Although anecdotal data provide a link between GLP-1 use and hair loss, present scientific data is still lacking certainty. Many cases might identify the dietary imbalances or physiological stress from weight loss rather than the drug itself.

It is essential to determine the fundamental cause of hair loss, as proper treatment depends on an accurate diagnosis. Lifestyle changes or medication adjustments under medical supervision, GLP-1 RAs could be taken into consideration. Where nutritional deficits are found, suitable supplements could help in the management of hair loss.

To guarantee both efficient weight control and the preservation of general health, including hair health, the article emphasises ultimately the need for a cooperative approach with healthcare specialists.