Thinking about your health and fertility often goes hand-in-hand. For many people, this includes considering your weight.

You might have heard about weight loss medications, specifically GLP-1 injections like semaglutide, tirzepatide, and liraglutide. While these medicines have gained attention for

Find out more about the effect of weight gain on fertility in our previous blog: ‘Does weight gain lead to fertility loss?’

their effectiveness in weight management, it's natural to wonder how they might fit into your family planning goals.

In this blog, we won’t be making any recommendations, but rather, providing you with friendly and informative insights to help you have a more informed conversation with your doctor.

How Weight Changes Can Affect Reproductive Health

Your fertility is closely linked to your overall health. Your menstrual cycle and the process of ovulation (the release of an egg from your ovary) are particularly sensitive to changes in calorie intake and body fat levels.

It’s a delicate balance. Being significantly overweight or underweight can disrupt the hormones that govern your cycle, potentially making it harder to conceive. For women aged 20–40, the healthy range for body fat percentage is around 21% to 32%.

Additionally, rapid changes in weight (either weight loss or gain) can affect your hormones, potentially affecting your fertility.

Effects of Weight Loss Treatments on Menstrual Cycles and Ovulation

So, where do weight loss treatments fit in? When you start a medication that leads to weight loss, it’s not uncommon to see changes in your menstrual cycle. Some people report that their periods become lighter, heavier, or more irregular. Others might even miss a period.

Why does this happen? In simple terms, these medications can influence the hormones that manage your menstrual cycle. Hormones like oestrogen and progesterone are sensitive to shifts in body weight and energy availability. As your body adjusts to the medication and weight loss, your hormonal patterns can shift, leading to these cycle changes. For many people, these changes are temporary, and their cycle returns to a more regular pattern as their weight stabilises or after they stop the treatment.

Potential Impact of Weight Loss Treatments on Fertility

We’ve talked about how weight loss treatments affect your menstrual cycle, but how do they affect your ability to get pregnant? The direct effect of these injections on fertility is still an area of ongoing research, meaning we don't have all the answers yet.

What we can consider is the indirect impact:

• The cons: As these treatments can cause irregular or missed ovulation, they could temporarily reduce your ability to get pregnant.
• The pros: Being overweight can also reduce fertility. Therefore, it's possible that achieving a healthier weight through gradual and moderate weight loss could lead to improved fertility for some people.

Things to Consider When Planning a Pregnancy

If you are thinking about starting a family, it’s crucial to be proactive. We always encourage speaking with your doctor about your goals for having children before starting any new medications, including weight loss treatments. If you're already taking one, that conversation is just as important.

It's all about balancing your weight management goals with your reproductive health. A great approach is to first focus on sustainable lifestyle changes, like a balanced diet and regular exercise, which can support both your overall health and your fertility, whether you're taking medication or not.

One very important point to be clear on: GLP-1 medications are not recommended for use if are trying to become pregnant, or if you’re currently pregnant. This is because there isn’t enough research to confirm their safety for a developing baby.

Different weight loss treatments recommend that you either stop using the medication at least two months before trying to conceive, or when you start trying. That’s why it’s important to check with your doctor so you can get advice relevant to your situation.

Conclusion

Navigating the world of weight management and fertility can feel complex, but you don't have to do it alone. The key takeaway is that while weight loss treatments can influence your menstrual cycle and potentially your fertility, the effects can vary greatly from person to person. For some people who are overweight, losing weight may even help to improve their fertility.

The most important step you can take is to have an open and honest conversation with your doctor. They can help you evaluate the pros and cons, understand the potential impacts on your personal health, and make informed choices that are right for you and your future family.

To find out more about what else may affect your fertility and how you may be able to improve your reproductive health, click here.