Weight loss injections, the class of medications that includes Semaglutide (Wegovy), Tirzepatide (Mounjaro) and Liraglutide, have become increasingly widely used for weight management and metabolic health. As more women use these medications alongside hormone replacement therapy or hormonal contraception, questions about how these treatments interact are becoming more important to address.
GLP-1 medications work by slowing gastric emptying, which means food and other substances move through the digestive system more slowly. This is relevant for oral medications including combined oral contraceptive pills and oral HRT preparations, because the rate at which a medication is absorbed can affect its efficacy. While the evidence base in this specific area is still developing, women using oral contraception alongside GLP-1 medications should be aware of this potential interaction and have medical advice from a doctor.
For women using transdermal HRT, meaning patches, gels, or sprays that are absorbed through the skin rather than the gut, this absorption concern does not apply in the same way. This is one of several reasons why transdermal HRT is often considered preferable for many women using weight loss injections. However, progesterone is often taken as a capsule and there are concerns how well this absorbs and how efficient it is at protecting the endometrial ( womb ) lining . Reduced absorption can lead to endometrial thickening and increase your risk of endometrial cancer in the future. It is essential that you discuss starting a GLP-1 medication with your women’ s health doctor so they can discuss alternatives.
There is also the question of nutritional adequacy. GLP-1 medications typically result in a significantly reduced appetite and food intake. During perimenopause and menopause, adequate intake of protein, calcium, vitamin D, and other nutrients becomes increasingly important for bone health, muscle maintenance, and overall wellbeing. If caloric intake is substantially reduced, ensuring that nutritional needs are still being met requires careful attention.
Weight loss achieved through GLP-1 medications can also affect hormone levels, since adipose tissue is involved in oestrogen production and metabolism. For women on HRT, this may mean that their hormonal requirements change as body composition shifts, which is another reason why ongoing medical review during this combination of treatments is important. At SHE Health, we assess each woman’s full picture when considering medical weight management alongside hormonal care. These are not separate conversations. They are part of the same one.
