Does Wegovy give you hot flashes — and what does the evidence say?

You've started Wegovy and noticed a wave of warmth, here's what that likely is

Picture this: a few weeks into treatment, you're sitting at your desk when a sudden flush of heat moves through your face and chest. Your first thought is Wegovy. And it might be right, just not in the way you expect.

The UK prescribing information for Wegovy does not list hot flashes as a recognised side effect. However, warmth and a feeling of overheating have been reported by some people using the medicine, and there is a plausible biological reason for it. Semaglutide acts on GLP-1 receptors in the hypothalamus, the part of the brain that controls appetite, but also body temperature. Activating those receptors appears, in some individuals, to produce a brief sensation of heat or flushing, distinct from a classical hot flash. According to the NHS medicines information for semaglutide, the confirmed common side effects are overwhelmingly gastrointestinal: nausea, vomiting, diarrhoea, constipation and indigestion top the list. Warmth is not in the same category.

That distinction matters. A hot flash linked to perimenopause or menopause has a specific hormonal origin: falling oestrogen destabilises the body's thermostat, producing sudden, intense heat, often with sweating, a racing heart, and redness. If you want to understand whether Wegovy can cause hot flashes specifically, the picture is more nuanced than a simple yes or no, and a Wegovy-related flushing sensation, if it occurs, tends to be milder and shorter-lived. If you're in your 40s or 50s and experiencing frequent, intense episodes, the menopause is the more likely explanation, and it is worth discussing with your GP separately.

Why the confusion is so common, and one myth worth letting go

There's a widely held assumption that weight-loss medicines cause hot flashes as a direct side effect, partly because GLP-1 drugs have become so talked-about that people attribute almost any physical change to them. It's understandable. When you start something new, every unfamiliar sensation gets assigned to it. In reality, most thermal sensations reported on Wegovy trace back to one of three things: the gastrointestinal effects of the medicine (digestion generates heat), the body's adjustment to reduced calorie intake, or an entirely separate hormonal process that was already underway.

Flushing can also follow an injection. Some people notice brief redness or warmth near the injection site after dosing, which is a local reaction rather than a systemic hot flash. Rotating your injection sites correctly can reduce localised reactions of this kind. None of this means your symptoms aren't real or worth attention, just that the cause may not be the medicine itself.

There is also a more specific question worth noting: Wegovy has been shown to have cardiovascular effects, including modest reductions in blood pressure. You can read more about that on our page covering Wegovy and blood pressure. Blood pressure changes can occasionally produce flushing sensations in some people, which is another route to the same symptom that has nothing to do with hormones.

When to tell your prescriber, and what they'll want to know

If hot flashes or heat episodes are frequent, intense, or disrupting your sleep, mention them at your next clinical review. That is true whether you suspect Wegovy or menopause or both. Your prescriber will want to know when the flashes started relative to your injection schedule, how long each episode lasts, whether sweating or palpitations accompany them, and what other medicines or hormonal treatments you are taking.

Women using HRT alongside Wegovy have an additional consideration: NHS England advises that transdermal HRT (patches or gels applied to the skin) may be preferable while taking tirzepatide for absorption reasons, though the same formal guidance does not apply to semaglutide. If you use oral HRT and are experiencing symptoms you cannot explain, it is worth asking whether your regimen needs reviewing. For GI symptoms that sometimes accompany heat (bloating and wind are among the more common complaints) there is separate guidance available.

The MHRA's Yellow Card scheme at yellowcard.mhra.gov.uk exists precisely for situations like this: if you believe a medicine is causing a symptom not listed in its information, reporting it helps regulators build a clearer picture over time.

Starting Wegovy through a regulated service, what the process looks like

Wegovy is a prescription-only medicine. A registered prescriber must assess your medical history, current symptoms, and other medications before it can be issued, and that assessment should happen before every repeat, not just at the start. If you are considering treatment and have questions about how symptoms like these would be handled, a free consultation is the right place to raise them.

At nume, a GPhC-registered Independent Prescriber reads every consultation personally on the same day it is submitted. There is no automated system making that call. You can explore what treatment involves (and whether it might be right for you) on our treatment consultation page, or read a broader overview of how Wegovy works as a starting point. Our clinical team is also available seven days a week if you have questions after starting treatment.