Mounjaro & Other Weight-Loss Drugs Advice

Mounjaro & Other Weight-Loss Drugs Advice (Contraception/Pregnancy/HRT)

 

At The Atherstone Surgery, we are dedicated to keeping our patients informed about any medications that may impact their health and well-being. We would like to share some important advice for women using GLP-1 agonist injections, such as tirzepatide (Mounjaro) or semaglutide (Ozempic), for weight management. This is especially important for those taking contraceptive pills, hormone replacement therapy (HRT), or planning a pregnancy.

 

Weight loss injections, also known as GLP-1 agonists, are prescription medications designed to assist individuals with obesity or excess weight in reducing their body weight or managing type 2 diabetes.

These injections work by mimicking a hormone called GLP-1, which plays a crucial role in regulating appetite and digestion. They stimulate an increase in insulin production, which slows down the digestion process in the stomach and enhances feelings of fullness. This helps control appetite, potentially leading to reduced food intake and weight loss. Additionally, the increased insulin levels help lower blood sugar, which is beneficial for controlling type 2 diabetes.

Typically, these medications are administered as injections on a weekly basis, and they should be used as part of a comprehensive weight management plan that includes a healthy diet and regular exercise.

Examples of GLP-1 medicines include:

• Semaglutide (Wegovy, Ozempic, Rybelsus)
• Liraglutide (Saxenda, Victoza, Diavic)
• Dulaglutide (Trulicity)
• Tirzepatide (Mounjaro, Zepbound*) Note: Tirzepatide acts on both GLP-1 and GIP receptors but has similar effects on stomach emptying.
• Exenatide (Bydureon BCise)
• Lixisenatide (Contained in Suliqua)

 

Whilst lower doses are available to be prescribed by your GP to aid in diabetes control, higher doses for weight management have some restrictions.

To be eligible, patients must have a Body Mass Index (BMI) of 40 or more (or 37.5 kg for people from minority ethnic family backgrounds) AND have been diagnosed with AT LEAST FOUR of the following long-term conditions:

• Hypertension (high blood pressure)
• High cholesterol or dyslipidaemia (abnormal fat levels in the blood)
• Obstructive sleep apnoea  (when your breathing stops and starts while you sleep)
• Cardiovascular disease (heart and blood vessel disease)
• Type 2 diabetes

 

For more details on who will become eligible over the coming years, see page 7 of the official NHS Guidance.

Due to the financial constraints facing the NHS and despite the NICE guidelines recommending tirzepatide (Mounjaro®) for weight management in eligible adults with obesity and related health issues, the NHS has had to adjust its guidance to align with available funding. As a result, you may not be able to access GLP-1 medications through the NHS.

If you believe you qualify and wish to start injections, please consult a healthcare professional. Before prescribing GLP-1 agonists, a clinician will discuss the benefits and limitations of the treatment, including any potential side effects.

If injections are recommended for weight loss, it is important to maintain a balanced, reduced-calorie diet and engage in regular physical activity while using the medication.

 

Other support is still available

We understand the frustration of those who want to access GLP-1 medications for weight loss through the NHS but are unable to do so. We recognise that managing weight can be challenging, but there are other support options available. We can refer you to alternative NHS weight management services.

If you would like more information about the help available, please visit the obesity section of our website below:

The Atherstone Surgery: Obesity and Weight Management 

 

We understand that many individuals are acquiring weight loss injections like Mounjaro (tirzepatide) and Wegovy (semaglutide) from private providers. However, providers such as Med Express, Simple Online Pharmacy, and Health Hero do not have access to a patient's complete medical history and depend exclusively on the information provided by the patient.

We want our patients to be aware that if you obtain weight loss medications from a private provider, your GP may not be informed about these prescriptions. This lack of communication can lead to potential hazards when these medications are combined with oral contraceptives and hormone replacement therapies. It is important to understand these interactions for your safety.

There is increasing evidence that weight loss injections may affect the absorption of certain medications, particularly oral hormonal medications used for contraception or hormone replacement therapy (HRT). These injections can delay stomach emptying, which may reduce the absorption of these medications and, consequently, their effectiveness.

For women taking the contraceptive pill, this can lead to an increased risk of unintended pregnancy. Additionally, for those on HRT, improper absorption may elevate the risk of womb cancer, especially in individuals with underlying conditions such as diabetes or polycystic ovary syndrome (PCOS).

Common side effects of Mounjaro include nausea, constipation, diarrhoea, indigestion, vomiting, headaches, hair loss, and dizziness. Though rarer, serious side effects may include gallbladder disease, pancreatitis, cardiovascular events, liver issues, cancer, kidney problems, and mood changes.

If you are using weight loss injections obtained privately, it is important that you have been informed about their potential interactions by the person who prescribed your medication. We wish to ensure you have received this information.

If you have any concerns or questions regarding contraception or hormone replacement therapy (HRT) while using weight loss injections, please discuss them with a healthcare professional. Additionally, if you are feeling unwell and are taking any privately prescribed medication, it is crucial to inform your clinician. This information will help them assess how your medication might impact their diagnosis and ensure you receive the care you need.

If you would like more specific information about the interactions between weight loss injections, contraception, pregnancy and HRT medications, please read further.

 

When using weight loss injections, it's important to be aware of potential interactions with oral contraceptives.

Medications like Wegovy or Mounjaro may decrease the effectiveness of both combined oral contraceptives and the mini-pill, as well as emergency contraception (the morning-after pill). This can increase your risk of an unplanned pregnancy because your body might not absorb the contraceptive pill properly while using tirzepatide (Mounjaro®) due to it’s slow stomach emptying properties.

 

Recommended Actions:

If you are using the contraceptive pill while also taking weight loss injections, current guidelines recommend using an additional method of contraception, such as a condom, for four weeks after starting the medication and for four weeks after any increase in dosage. For optimal protection against unwanted pregnancy, consider switching to a non-oral contraceptive option while using Mounjaro.

GLP-1 agonists do not interfere with non-pill contraception methods, so it is safe to use these options without any extra precautions when taking a GLP-1 agonist.

Suitable alternatives to the contraceptive pill include:

• Condoms
• Coil (IUD)
• Depo injection (Depo can be used but can be associated with weight gain so may not be advisable if Mounjaro is being taken for weight loss purposes).
• Implant (Nexplanon)

If you are using a weight loss injection from a non-NHS provider, are sexually active and on the pill, please speak to your weight loss prescriber regarding this, or alternatively contact your GP, family planning clinic or local sexual health centre to discuss other contraceptive choices.

 

Does this advice apply to all weight loss medicines?

For certain medications like semaglutide, exenatide, liraglutide, dulaglutide, and lixisenatide, there is no evidence to suggest that they reduce the effectiveness of oral contraceptives.

While some injections, such as Mounjaro, can potentially affect the absorption of oral contraceptives, semaglutide does not have this interaction. It is always advisable to use effective contraception while taking any weight loss medication. Some sources recommend using a non-oral contraceptive method, such as barrier methods like condoms, for added safety, especially during the initial treatment phase and when increasing the dose.

 

I have diarrhoea and vomiting with my GLP-1 agonist, and I take the contraceptive pill, what should I do?

Diarrhoea and vomiting can happen when taking GLP-1 agonists and might make the pill less effective. Those using oral contraception who experience vomiting or severe diarrhoea as a side-effect should follow the missed pills guidance in the pill packet. If diarrhoea or vomiting continues, think about using a different type of contraception that isn’t a pill, or use condoms as well.

 

I am planning to switch from one type/brand of GLP-1 to another, does the contraception advice remain the same?

If you are changing to tirzepatide (Mounjaro) from any other GLP-1 agonist, use condoms for four weeks after switching and for four weeks after any dose increase. Keep taking your pill too. Or, you might want to switch to a different type of contraception that isn’t a pill while using tirzepatide.

 

I need emergency contraception and I’m taking a GLP-1 agonist; will it work?

We don’t know yet if GLP-1 agonists affect emergency contraception pills. The copper IUD (coil) is the best emergency contraception and isn’t affected by diarrhoea or vomiting. If you need emergency contraception, tell your healthcare provider about all the medicines you’re taking, including GLP-1 agonists.

 

It’s important to use good contraception when taking a GLP-1 agonist because these medicines shouldn’t be used if you’re pregnant, trying to conceive, or breastfeeding. Currently, there is a lack of safety data on the use of weight loss injections during pregnancy and breastfeeding. There are concerns that these drugs can harm a developing pregnancy.

GLP-1 agonists should be avoided for a number of weeks prior to a planned pregnancy. The table below shows how many weeks you should stop the medicine before planning a pregnancy for some GLP-1 agonists.

• Tirzepatide (Mounjaro) - One month 
• Semaglutide (Ozempic, Wegovy, Rybelsus) - Two months 
• Exenatide (Byetta, Bydureon BCise) - 12 weeks

 

 

If you are taking oral progestogens as part of your hormone replacement therapy (HRT), such as Utrogestan, Norethisterone, or Medroxyprogesterone, it is important to be aware that tirzepatide (Mounjaro) may affect the effectiveness of your HRT.

Injectable weight loss medications like tirzepatide can delay gastric emptying, which may reduce the absorption of oral progestogens. This could lead to decreased effectiveness or variations in how your body responds to the treatment.

Progesterone is commonly used in HRT for women with a uterus to mitigate the risks associated with oestrogen therapy alone, particularly regarding the health of the uterine lining.  As a result, your HRT may not adequately protect your endometrium (the lining of the uterus), potentially increasing your risk of cancer.

If weight loss injections cause your HRT to be less effective, it can also cause your menopause symptoms to come back, like:

• Hot flushes
• Night sweats
• Mood changes
• Trouble sleeping

Currently, there is no specific warning from the MHRA regarding Hormone Replacement Therapy (HRT); however, the same precautions that apply to any oral medication should be considered. NICE guidelines recommend personalizing HRT to meet individual needs, which may mean that for some individuals, switching from tablets to an alternative form of HRT is safer.

If you are not taking your HRT orally—such as using a patch, gel, or Mirena coil—there's no need for concern. Transdermal or vaginal methods are unlikely to cause interactions.

 

Recommendations:

If you are taking oral hormone replacement therapy (HRT) along with a GLP-1 agonist, we recommend scheduling an HRT review with your GP practice. This appointment will allow us to discuss your treatment options and ensure your ongoing protection and well-being.

You may need an adjustment in your dosage or a switch to a different form of medication. However, please be aware that there is some uncertainty regarding the appropriate dosage increase and whether merely increasing the dose will ensure safety.

Given this uncertainty, it is advised that women switch to a non-oral progestogen, such as combined patches, gels, sprays, or an intrauterine device (IUD) like the Mirena coil. These alternatives bypass the stomach and are not impacted by injectable weight loss medications, making them more suitable for use in this context.

The Mirena IUD is particularly recommended, especially for individuals with obesity, as they face a higher risk of endometrial cancer. The Mirena is very effective at protecting the lining of the womb from this risk.

All these points should have been discussed with you by your private provider prior to commencing an injectable weight loss medication and at every dose change. But if you are using the injections and have any concerns about the above or would like to change your contraception or HRT, please don’t hesitate to contact your surgery.

 

Will GLP-1 Affect a scheduled procedure?

Yes, GLP-1 medications such as Ozempic and Wegovy can impact scheduled procedures, particularly those requiring general anaesthesia or deep sedation. This is because these medications can delay gastric emptying, which increases the risk of pulmonary aspiration (the inhalation of stomach contents into the lungs) during anesthesia.

Before undergoing any surgical procedure, it is essential to inform your healthcare team, including the anaesthesiologist, if you are taking liraglutide, semaglutide, or tirzepatide (Mounjaro).

 

• Gov.co.uk Weightloss Medicine Guidance 
• Gov.co.uk skinny Jabs and contraception latest guidance: Women on “skinny jabs” must use effective contraception, MHRA urges in latest guidance  – GOV.UK      
• British Heart Foundation: Weight-loss injections Explained
• NHS UK: Obesity Treatment 
• PCWHS Injectable weight loss drugs, contraception and HRT (PDF)

 

Much of the patient information included above is based on a leaflet from the Faculty of Sexual and Reproductive Healthcare (FSRH) and the Primary Care Women’s Health Society, which can be found below.     

Faculty of Sexual and Reproductive Healthcare (FSRH) and the Primary Care Women’s Health Society.

This is for information only and should not be a substitute for seeking medical advice. Decisions regarding your contraception choices should always include discussion with a healthcare professional, particularly if you have any questions or concerns. No contraception is 100% effective and there is always a risk of pregnancy. The Faculty of Sexual and Reproductive Healthcare bears no liability for the choices an individual makes regarding contraception or the outcome of their decision.