Can Wegovy Cause Hair Loss in Females?

Does semaglutide itself cause hair loss, or is something else going on?

This is a question our prescribers hear most weeks, and the honest answer is: both the medicine and the weight loss it produces are likely involved. Semaglutide (the active ingredient in Wegovy) reduces appetite and slows gastric emptying, which often leads to a significant drop in calorie intake, particularly in the early months. Rapid weight loss, whatever its cause, is a well-recognised trigger for telogen effluvium: a process in which a larger-than-usual proportion of hair follicles shift prematurely into the resting (shedding) phase of their growth cycle.

In the STEP 1 trial, published in the New England Journal of Medicine, hair loss was recorded as an adverse event in a proportion of participants taking 2.4mg semaglutide weekly over 68 weeks. It was not among the most common effects (that distinction belongs to the gastrointestinal group) but it was sufficiently consistent to be included in the licensed product information. The NHS medicines page for semaglutide lists alopecia (hair loss) as an uncommon side effect, meaning it affects fewer than 1 in 100 but more than 1 in 1,000 people. Worth knowing: the threshold for listing a side effect in official documentation is not the same as it being inevitable or even likely for most users.

The fuller picture of how Wegovy's side effects present in females suggests hormonal factors, pre-existing nutritional status and the pace of weight loss all interact. Women are generally more prone to telogen effluvium than men, which is why this question arises more often in this group.

When during treatment does hair shedding typically appear, and does it resolve?

Telogen effluvium has a characteristic delay. The stressor (in this case, rapid calorie restriction or significant weight change) usually precedes the visible shedding by two to four months. That timing catches people off guard. Someone who started Wegovy in January and notices increased shedding in March or April may not immediately connect the two.

The reassuring pattern, consistent with what is understood about telogen effluvium generally, is that shedding tends to peak and then gradually slow as the body adapts and weight loss stabilises. For most people it resolves within six months of onset without any specific treatment. Hair regrowth follows, though the timeline varies between individuals. You can read more about practical approaches to managing hair loss during Wegovy treatment if this is a current concern.

Whether shedding does resolve also depends on whether an underlying nutritional deficit is corrected. Protein is the structural building block of hair. On a significantly reduced calorie intake, many people eat less protein than their body needs to maintain hair cycling normally. Adequate hydration, iron levels (particularly relevant for women who menstruate) and zinc status are also factors that a prescriber or dietitian can assess. If you are wondering whether taking semaglutide can directly cause hair loss, we look at the evidence in detail on that page. The broader question of whether Wegovy causes hair loss at a population level has been examined in post-marketing surveillance as well as trial data.

Are there signs that hair loss needs prompt medical attention?

Most shedding associated with semaglutide is diffuse, noticeable in the shower tray or brush, spread evenly across the scalp rather than in patches. That pattern is consistent with telogen effluvium and, while distressing, is not medically urgent. There are circumstances, though, where a prescriber should be told promptly.

Seek medical review if: hair loss is patchy or includes eyebrows and lashes (which could suggest alopecia areata or another condition); shedding continues beyond four to six months with no sign of slowing; you develop other new symptoms alongside hair loss (fatigue, cold intolerance or significant changes in mood, which could point to a thyroid issue); or the degree of loss is causing you significant distress. The broader safety profile of semaglutide covers a range of effects worth understanding before and during treatment.

For any suspected medicine side effect, the MHRA's Yellow Card scheme lets patients and healthcare professionals report reactions directly. This is how the UK's drug safety picture is built, your report genuinely contributes. The full Wegovy side effects overview covers the complete list from nausea to rarer concerns, with the same measured framing.

Discussing hair shedding as part of your initial consultation is sensible. Our prescribers at numeour clinical team discuss suitability and known side effects including this one before any treatment is issued, it is part of the clinical assessment, not an afterthought. If you would like to explore whether Wegovy is appropriate for you, start a free consultation and a GPhC-registered prescriber will review your answers the same day.