Wegovy (semaglutide 2.4 mg) is a GLP-1 receptor agonist licensed in the UK for weight management in adults with obesity or overweight with comorbidities. As with any medication, patients may wonder about potential side effects, including whether Wegovy can cause ovarian cysts. This concern is particularly relevant for women of reproductive age considering or currently taking this treatment. This article examines the available clinical evidence, explores recognised side effects in women, and provides guidance on when to seek medical advice whilst taking Wegovy.

Understanding Wegovy and Its Mechanism of Action

Wegovy (semaglutide 2.4 mg) is a prescription medicine licensed in the UK for weight management in adults with obesity or those who are overweight with at least one weight-related comorbidity. It belongs to a class of medications called glucagon-like peptide-1 (GLP-1) receptor agonists, which were originally developed for type 2 diabetes management but have demonstrated significant efficacy in promoting weight loss.

The mechanism of action centres on mimicking the naturally occurring hormone GLP-1, which is released from the intestine in response to food intake. Semaglutide binds to GLP-1 receptors in multiple tissues throughout the body, including the pancreas, brain, and gastrointestinal tract. In the pancreas, it enhances glucose-dependent insulin secretion whilst suppressing inappropriate glucagon release, thereby improving glycaemic control. Within the central nervous system, particularly in appetite-regulating centres of the hypothalamus, semaglutide reduces hunger signals and increases feelings of satiety.

Additionally, Wegovy slows gastric emptying, which prolongs the sensation of fullness after meals and contributes to reduced caloric intake. This multi-faceted approach results in substantial weight reduction—clinical trials in the STEP programme have demonstrated average weight loss of approximately 15% of initial body weight over 68 weeks when combined with lifestyle interventions, though individual results may vary.

Wegovy is administered as a once-weekly subcutaneous injection, with dosing gradually escalated over a standard 16-week titration period (which may be extended if not tolerated). According to NICE guidance (TA875), Wegovy is recommended for use within specialist weight management services with multidisciplinary support. Eligibility typically requires a body mass index (BMI) of 35 kg/m² or above, or 30 kg/m² with weight-related complications, and treatment is usually limited to 2 years. Understanding how this medication works systemically is essential when evaluating potential effects on reproductive health.

Can Wegovy Cause Ovarian Cysts? Examining the Evidence

When considering whether Wegovy can cause ovarian cysts, it is important to examine the available clinical evidence carefully. There is currently no established causal link between semaglutide (Wegovy) and the development of ovarian cysts based on data from large-scale clinical trials and post-marketing surveillance.

The pivotal STEP (Semaglutide Treatment Effect in People with obesity) clinical trial programme, which included thousands of participants, did not identify ovarian cysts as a recognised adverse effect of semaglutide. The Summary of Product Characteristics (SmPC) for Wegovy, as approved by the MHRA and European Medicines Agency (EMA), does not list ovarian cysts among the documented side effects. This regulatory documentation is based on comprehensive safety data collected during clinical development and ongoing pharmacovigilance.

However, it is worth noting that weight loss itself—regardless of the method—can influence reproductive hormone balance in women. Significant weight reduction may affect oestrogen levels, menstrual regularity, and ovarian function, particularly in women with polycystic ovary syndrome (PCOS) or other underlying reproductive conditions. In some cases, weight loss can actually improve ovarian function and reduce existing cysts in women with PCOS, rather than causing new ones.

There have been isolated anecdotal reports from patients taking GLP-1 receptor agonists who subsequently developed ovarian cysts, but correlation does not imply causation. Ovarian cysts are relatively common in women of reproductive age, with functional cysts occurring as part of normal ovarian activity in many cases. Without controlled studies specifically examining this relationship, any temporal association may be coincidental.

Healthcare professionals should maintain awareness that whilst there is no official link, individual patient experiences warrant investigation, and any new pelvic symptoms should be evaluated on their clinical merits rather than automatically attributed to medication. Clinicians should follow standard clinical pathways for investigating pelvic symptoms, regardless of whether the patient is taking Wegovy.

Recognised Side Effects of Wegovy in Women

Wegovy, like all medications, carries a profile of recognised side effects that have been documented through clinical trials and real-world use. Understanding these established adverse effects is important for women considering or currently taking this medication.

Gastrointestinal effects are the most commonly reported side effects, affecting the majority of users to some degree. These include:

• Nausea (affecting up to 44% of users initially)

• Diarrhoea (approximately 30% of users)

• Vomiting (24% of users)

• Constipation (24% of users)

• Abdominal pain and bloating

These symptoms typically emerge during dose escalation and often diminish over time as the body adjusts to the medication. Eating smaller, more frequent meals, avoiding rich or spicy foods, and staying well-hydrated can help manage these effects.

Reproductive and hormonal considerations specific to women include potential effects on contraception. According to the UK SmPC, semaglutide does not have a clinically relevant effect on the exposure of oral contraceptives. However, if severe vomiting or diarrhoea occurs, the effectiveness of oral contraceptives may be reduced, and additional contraceptive methods are advised during and shortly after these episodes, in line with general contraceptive guidance. Furthermore, Wegovy should be discontinued at least two months before a planned pregnancy due to limited safety data in pregnancy. If pregnancy occurs or is suspected while taking Wegovy, the medication should be stopped immediately and the prescriber contacted.

Other recognised side effects include:

• Fatigue and dizziness

• Headache

• Injection site reactions (redness, itching)

• Increased heart rate (typically modest)

• Gallbladder problems, including gallstones and cholecystitis (risk increased with rapid weight loss)

• Hypoglycaemia (mainly when used alongside insulin or sulfonylureas in people with diabetes)

• Risk of dehydration and acute kidney injury with severe gastrointestinal symptoms

• Diabetic retinopathy complications in people with pre-existing retinopathy

Rare but serious adverse effects include pancreatitis (inflammation of the pancreas), which requires immediate medical attention if severe abdominal pain develops. Animal studies have shown an increased incidence of thyroid C-cell tumours with semaglutide, though the human relevance of this finding is unknown according to the UK SmPC.

If you experience any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in the package leaflet. You can also report side effects directly via the Yellow Card Scheme at yellowcard.mhra.gov.uk.

Ovarian Cysts: Causes, Symptoms, and Risk Factors

Ovarian cysts are fluid-filled sacs that develop on or within an ovary. They are remarkably common, with most women of reproductive age developing at least one during their lifetime. Understanding the nature of these cysts helps contextualise any concerns about potential medication effects.

Types and causes of ovarian cysts include:

Functional cysts are the most common type, arising from the normal menstrual cycle. Follicular cysts form when a follicle fails to rupture and release an egg, whilst corpus luteum cysts develop when the corpus luteum (the structure remaining after ovulation) fills with fluid. These typically resolve spontaneously within one to three menstrual cycles without intervention.

Pathological cysts are less common and include dermoid cysts (containing tissue such as hair or skin), cystadenomas (developing from ovarian surface cells), and endometriomas (associated with endometriosis). Polycystic ovaries, characteristic of PCOS, involve multiple small follicles that fail to mature properly, often associated with hormonal imbalance, insulin resistance, and metabolic dysfunction.

Common symptoms of ovarian cysts vary considerably. Many cysts are asymptomatic and discovered incidentally during pelvic examinations or ultrasound scans for other reasons. When symptoms do occur, they may include:

• Pelvic pain or discomfort—ranging from dull aching to sharp pain, often on one side

• Bloating or abdominal swelling

• Pain during intercourse (dyspareunia)

• Irregular menstrual periods or changes in menstrual flow

• Difficulty emptying the bladder completely

• Pressure on the bowel, causing constipation

Risk factors for developing ovarian cysts include hormonal imbalances, previous ovarian cysts, endometriosis, pelvic infections, and PCOS. Interestingly, obesity itself is associated with increased risk of PCOS and related ovarian dysfunction, which means that women seeking weight management treatment may already have underlying risk factors independent of any medication.

Complications, whilst uncommon, include ovarian torsion (twisting of the ovary, cutting off blood supply—a surgical emergency), cyst rupture causing acute pain and internal bleeding, and rarely, malignant transformation in certain cyst types, particularly in postmenopausal women. Management approaches differ between pre- and postmenopausal women, with postmenopausal ovarian cysts requiring more careful evaluation due to higher risk of malignancy.

When to Seek Medical Advice While Taking Wegovy

Women taking Wegovy should be aware of specific symptoms and circumstances that warrant prompt medical evaluation. Whilst the medication is generally well-tolerated, certain warning signs require professional assessment.

Seek urgent medical attention (contact 999 or attend A&E) if you experience:

• Severe, sudden abdominal or pelvic pain—particularly if accompanied by nausea, vomiting, or fever, which could indicate ovarian torsion, cyst rupture, or other acute abdominal emergencies

• Severe, persistent upper abdominal pain radiating to the back, potentially indicating pancreatitis

• Signs of allergic reaction—facial swelling, difficulty breathing, or widespread rash

• Symptoms of gallbladder inflammation—severe right upper abdominal pain, particularly after eating, with fever or jaundice

Contact your GP or prescribing clinician within 24–48 hours if you notice:

• New or worsening pelvic pain or pressure that persists beyond a few days

• Significant changes in menstrual patterns—particularly irregular bleeding, unusually heavy periods, or amenorrhoea (absence of periods)

• Persistent bloating or abdominal distension that is new or progressive

• Unexplained weight gain despite taking Wegovy, or inability to lose weight as expected

• Persistent gastrointestinal symptoms that interfere with daily activities or nutrition

• Signs of dehydration—dark urine, dizziness, reduced urination—particularly if experiencing vomiting or diarrhoea

• If you become pregnant or suspect pregnancy—stop Wegovy immediately and contact your prescriber

Routine monitoring recommendations include attending scheduled follow-up appointments with your prescribing clinician, typically every 3–6 months. These appointments assess weight loss progress, medication tolerance, and any emerging concerns. Women with pre-existing PCOS or other reproductive conditions may benefit from more frequent monitoring.

If you develop symptoms suggestive of ovarian cysts whilst taking Wegovy, your GP will likely arrange appropriate investigations. For persistent bloating, early satiety, pelvic or abdominal pain, or urinary urgency, your GP should arrange a CA-125 blood test. If the CA-125 level is 35 IU/mL or higher, an urgent ultrasound scan will be arranged, and you may be referred via the two-week wait pathway if ovarian cancer is suspected. This investigation pathway helps determine whether cysts are functional (likely to resolve spontaneously) or require further management.

Do not discontinue Wegovy abruptly without medical advice if you develop concerns. Discuss any symptoms with your healthcare provider, who can assess whether they are related to the medication, require investigation, or represent coincidental findings requiring separate management. Maintaining open communication with your healthcare team ensures both the benefits of weight management and appropriate monitoring of reproductive health.

If you experience any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in the package leaflet. You can also report side effects directly via the Yellow Card Scheme at yellowcard.mhra.gov.uk.

Frequently Asked Questions