Can Trulicity affect your period? Trulicity (dulaglutide) is a GLP-1 receptor agonist licensed in the UK for type 2 diabetes. Whilst menstrual changes are not listed as a recognised side effect in the official Summary of Product Characteristics, some women report alterations to their periods after starting treatment. These changes are more likely related to metabolic improvements—such as weight loss and better blood sugar control—rather than direct drug effects. Women with type 2 diabetes often experience menstrual irregularities due to insulin resistance and obesity. When metabolic health improves, hormonal balance may shift, potentially affecting cycle regularity, flow, or fertility.

Can Trulicity Affect Your Period?

Trulicity (dulaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for the treatment of type 2 diabetes mellitus. According to the official Summary of Product Characteristics (SmPC) approved by the Medicines and Healthcare products Regulatory Agency (MHRA), menstrual cycle changes are not listed as a recognised adverse effect of this medication. However, some women anecdotally report alterations to their periods after starting Trulicity.

Trulicity works by mimicking the action of incretin hormones, which stimulate insulin secretion in a glucose-dependent manner, suppress glucagon release, and slow gastric emptying. These effects help improve glycaemic control and often lead to weight loss—a common secondary benefit observed in clinical trials. It is these metabolic changes, rather than the drug itself, that may influence menstrual regularity. Women with type 2 diabetes frequently experience menstrual irregularities due to insulin resistance, obesity, and associated conditions such as polycystic ovary syndrome (PCOS). When metabolic health improves with treatment, hormonal balance may shift, leading to changes in cycle length, flow, or symptoms.

Additionally, gastrointestinal side effects—including nausea, vomiting, and diarrhoea—are common with Trulicity, particularly during the initial weeks of treatment. These symptoms can affect nutritional status and overall wellbeing, which may indirectly influence menstrual patterns. If you notice changes to your period after starting Trulicity, it is important to consider the broader context of your metabolic health, weight changes, and any other medications or health conditions that may be contributing factors.

Importantly, if your menstrual cycles become more regular while taking Trulicity, this may restore fertility. If pregnancy is not planned, ensure you are using effective contraception.

Weight Loss, Blood Sugar and Menstrual Changes

Weight loss is one of the most significant metabolic effects associated with Trulicity and other GLP-1 receptor agonists. Clinical trials have demonstrated weight reductions that vary by dose, with higher doses generally producing greater effects. For women with obesity and type 2 diabetes, even modest weight loss can have profound effects on reproductive hormones. Adipose tissue is metabolically active and produces oestrogen through the aromatisation of androgens. As body fat decreases, oestrogen levels may fluctuate, potentially leading to changes in menstrual cycle regularity, flow volume, or premenstrual symptoms.

Improved glycaemic control is another key factor. Chronic hyperglycaemia and insulin resistance disrupt the hypothalamic-pituitary-ovarian axis, which regulates the menstrual cycle. High insulin levels stimulate ovarian androgen production and reduce sex hormone-binding globulin (SHBG), leading to elevated free testosterone. This hormonal imbalance is particularly relevant in women with PCOS, a condition closely linked to insulin resistance and type 2 diabetes. When Trulicity improves blood glucose levels, the hormonal environment may normalise, sometimes restoring ovulation in women who previously had anovulatory cycles.

Conversely, some women may experience temporary disruptions as their body adjusts to these metabolic shifts. Stress on the body from gastrointestinal side effects, changes in appetite, or significant caloric restriction can affect the hypothalamic-pituitary axis, potentially causing delayed or missed periods. In cases of rapid weight loss or very low energy intake, functional hypothalamic amenorrhoea may occur. It is important to recognise that these changes often reflect the body's adaptation to improved metabolic health rather than a harmful drug effect. However, any persistent or concerning menstrual changes warrant medical review to exclude other causes.

If your periods become more regular and ovulation resumes, be aware that your fertility may increase. Consider appropriate contraception if you are not planning a pregnancy.

When to Speak to Your GP About Period Changes

Whilst some menstrual changes may be expected when starting Trulicity, certain symptoms require prompt medical attention. You should contact your GP or diabetes specialist nurse if you experience:

• Heavy menstrual bleeding (menorrhagia) — soaking through a pad or tampon every hour for several consecutive hours, passing large clots, or bleeding lasting longer than seven days

• Severe pelvic pain — particularly if it is new, worsening, or accompanied by fever, which could indicate infection or other gynaecological conditions

• Complete absence of periods (amenorrhoea) for three months or more, especially if you have previously had regular cycles

• Intermenstrual or postcoital bleeding — any bleeding between periods or after sexual intercourse should always be investigated

• Symptoms of pregnancy — if there is any possibility of pregnancy, as GLP-1 receptor agonists are not recommended during pregnancy

Seek emergency care immediately if you experience very heavy bleeding with dizziness or fainting, severe abdominal pain with bleeding in early pregnancy (possible ectopic pregnancy), or signs of shock.

Your GP may wish to perform a clinical assessment including a menstrual history, examination, and appropriate investigations. For amenorrhoea or unexpected bleeding, a pregnancy test is typically the first step. For heavy menstrual bleeding, a full blood count to check for anaemia is recommended by NICE guidance. Other tests such as thyroid function, sexually transmitted infection screening, or pelvic ultrasound may be arranged based on your symptoms and clinical presentation. Cervical screening status will be reviewed for those with intermenstrual or postcoital bleeding.

It is also important to discuss any menstrual changes with your diabetes team, as they can review your overall treatment plan and consider whether adjustments are needed. If you become pregnant while taking Trulicity, stop the medication immediately and contact your healthcare team, as it is not recommended during pregnancy. Do not stop taking Trulicity without medical advice in other circumstances, as this could compromise your diabetes control. You can report suspected side effects to the MHRA through the Yellow Card scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

Managing Your Diabetes Treatment and Menstrual Health

Balancing effective diabetes management with menstrual health requires a holistic, patient-centred approach. If you experience menstrual changes after starting Trulicity, keeping a detailed symptom diary can be invaluable. Record the dates, duration, and heaviness of your periods, along with any associated symptoms such as pain, mood changes, or gastrointestinal effects. This information will help your healthcare team identify patterns and determine whether the changes are related to the medication, weight loss, improved metabolic control, or another underlying cause.

Lifestyle modifications play a crucial role in supporting both diabetes management and menstrual health. A balanced diet rich in whole grains, lean proteins, healthy fats, and plenty of vegetables helps stabilise blood sugar levels and provides essential nutrients for hormonal balance. Regular physical activity—aiming for at least 150 minutes of moderate-intensity exercise per week, as recommended by the UK Chief Medical Officers—improves insulin sensitivity, supports weight management, and can help regulate menstrual cycles. Adequate sleep and stress management are equally important, as chronic stress and sleep deprivation can disrupt both glucose metabolism and reproductive hormones.

If menstrual symptoms are troublesome, your GP may suggest treatment options. For heavy menstrual bleeding, NICE recommends the levonorgestrel-releasing intrauterine system (LNG-IUS) as first-line treatment where appropriate. Other options include tranexamic acid, non-steroidal anti-inflammatory drugs like mefenamic acid, or hormonal contraceptives to regulate your cycle. Most hormonal contraceptives are suitable for women with diabetes who don't have vascular complications, but your healthcare team can advise on the most appropriate choice for your individual circumstances.

Regular monitoring is essential. Attend all scheduled diabetes reviews and ensure your HbA1c, weight, and blood pressure are checked as recommended. If you are planning a pregnancy, discuss this with your healthcare team well in advance. Trulicity should be discontinued at least one month before a planned pregnancy, according to the SmPC, and alternative diabetes management strategies implemented. Use effective contraception while taking Trulicity to prevent unplanned pregnancy. By maintaining open communication with your GP, diabetes specialist nurse, and other healthcare professionals, you can optimise both your metabolic health and menstrual wellbeing whilst continuing to benefit from effective diabetes treatment.

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