Using a contraceptive injection alongside weight loss injections

You're on the contraceptive injection and wondering if it still works

This is a question our prescribers hear regularly. The short answer is reassuring: the contraceptive injection, such as Depo-Provera (medroxyprogesterone acetate), delivers hormones directly into muscle tissue. From there, they absorb gradually into the bloodstream, a process that bypasses the gut entirely. GLP-1 medicines like tirzepatide and semaglutide slow gastric emptying, which affects how pills are absorbed through the stomach lining. Depot injections do not go anywhere near that pathway.

NHS England's guidance on weight management injections confirms that the contraceptive absorption concern is specifically about oral hormonal contraceptives used alongside tirzepatide. Women on the pill are advised to use an additional non-oral method (such as condoms) for the first four weeks of Mounjaro treatment and for four weeks after each dose increase. That precaution does not apply if your contraception is already non-oral, including the injection, patch, ring, implant, or hormonal coil.

So if you are on the contraceptive injection, your contraception should continue to work as normal. That said, tell your prescriber or the clinician reviewing your consultation, because your full medical history always informs the decision. You can read more about contraindications to weight loss injections more broadly on the contraindications page.

Weight loss and your hormones: what might still change

Even without any interaction between the two medicines, losing a significant amount of weight can affect your body in ways that touch on hormonal health. Some people notice changes to their menstrual cycle during GLP-1 treatment, cycles that had been irregular may become more regular as weight falls, particularly if polycystic ovary syndrome was a factor. Others notice temporary disruption. Neither outcome is guaranteed, and the picture varies from person to person.

The contraceptive injection itself can cause irregular periods or none at all, so it may be difficult to notice changes. What matters is that you keep your GP or specialist in the loop, especially if you are monitoring your cycle for any reason. If you are planning to conceive in the future, both Mounjaro and Wegovy require a wash-out period first, your prescriber can advise on timing, and MHRA guidance supports using reliable contraception throughout treatment and for a period afterwards.

If you are currently pregnant, breastfeeding, or actively trying to conceive, GLP-1 weight loss medicines are not suitable. That is a hard stop in the clinical guidance, not a grey area. The weight loss injection overview covers this in more detail.

What happens at your consultation if you mention the contraceptive injection

At nume, every consultation is personally reviewed by a GPhC-registered Independent Prescriber. Not software. A clinician reads your answers, checks your medical history, and asks about everything that might be relevant, including your current contraception. Mentioning the depot injection is straightforward: it does not create the same flag that oral contraceptives do, but it is part of the picture your prescriber needs.

If you order before midday on a working day, your consultation is reviewed the same day and, if you are approved, treatment is dispatched with free tracked next-working-day delivery via DPD. Some patients time this around payday, or place a Monday order to have treatment arrive by Tuesday, worth knowing if routine helps you. Everything is included in one transparent price: consultation, prescription, delivery, and 7-day aftercare. There is no subscription.

Our clinical team follows UK prescribing standards and GPhC guidance on identity and weight verification. If you want to understand how treatment options compare before you start, the most effective weight loss injection page sets out what the trial evidence shows. And if cost is a consideration, the weight loss injection prices page explains how private pricing works in the UK.

What is still uncertain, and who to talk to

Clinical guidance is clear on the oral contraceptive interaction. It is less detailed on every hypothetical scenario, for example, if you are switching contraceptive methods, timing around a dose increase, or managing multiple medicines. These are the situations where a single confident answer from a webpage is not enough.

Your GP knows your full medical history. Your prescriber at a regulated pharmacy can review your consultation answers in context. If you have complex needs, a specialist (such as a gynaecologist or endocrinologist) may be the right person to involve. If you are considering a newer option, you can find out more about how the monzo weight loss injection fits into the current landscape alongside any clinical conversation you have.

If at any point during treatment you experience unexpected symptoms (severe stomach pain, signs of allergic reaction, or anything that worries you) get medical help promptly. You can also report suspected side effects through the MHRA Yellow Card scheme. For those who want to explore how services are structured, our page on getting weight loss injections without needing to contact a GP explains what that process looks like at a regulated pharmacy. For general questions about what treatment through nume involves, the FAQs page is a good starting point.