Weight loss injections and HRT: What You Need to Know

If you are taking hormone replacement therapy (HRT) and are considering or already using incretin-based therapies such as semaglutide  (Ozempic) or tirzepatide (Mounjaro), it’s important to be aware of how these medications might interact. The British Menopause Society has recently released guidance to help women and clinicians navigate this safely.

Why It Matters

Incretin-based therapies, often used to support weight management and blood sugar control, can slow the way your stomach empties. This may reduce how much of an oral HRT hormone gets absorbed, including both oestrogen and progestogen.

Progestogen in HRT is essential if you have a uterus, as it protects the lining of the womb (endometrium) from thickening and reduces the risk of endometrial cancer. If absorption is reduced, the endometrial protection may be compromised.

Oral vs Non-Oral HRT

• Oral HRT (pills): Most affected by incretin-based therapies. Reduced absorption may lead to unscheduled bleeding or a return of menopausal symptoms such as hot flashes, night sweats, or mood changes.

• Non-oral HRT (patches, vaginal, intrauterine systems): Not expected to be affected. These include:
  • Transdermal progestogen patches (e.g., Evorel Sequi®, Femseven Conti®)
  • Intrauterine progestogen devices (e.g., Mirena®, Levosert®)
  • Vaginal or off-label use of oral Utrogestan

If you are using a non-oral progestogen, your HRT is unlikely to be affected by these therapies.

What This Means for You

This does not mean you have to stop using GLP-1 medications or HRT — both can still be used safely and effectively. However, your treatment plan might need a simple adjustment to keep you well protected.

What You Can Do

If you are on an oral HRT progestogen and start or are using an incretin-based therapy:

1. Speak to your HRT prescriber to ensure they are aware.
2. Discuss switching to a non-oral HRT progestogen, which is unaffected.
3. If switching isn’t possible, your doctor may increase your oral progestogen dose temporarily during the therapy.
4. Monitor for any unscheduled bleeding. If it occurs book a review with your doctor.

Oestrogen Considerations

Oral estrogen absorption might also be slightly reduced, potentially causing mild recurrence of menopausal symptoms or spotting. This is generally not harmful but may be inconvenient. Some women may choose to switch to transdermal oestrogen to avoid these effects.

Key Takeaways

• Incretin-based therapies can affect oral HRT hormone absorption, especially progestogens.
• Non-oral HRT options are safer in this context.
• Switching route or temporarily adjusting the oral progestogen dose may be advised.
• Unscheduled bleeding should always be reported to your doctor for review.
• Staying in touch with your menopause specialist ensures your HRT remains safe and effective.

👉 Read the full BMS guidance here.