Does HRT cause weight gain at menopause?

HRT, also known as hormone replacement therapy, is a common treatment used to relieve the symptoms of menopause. This is by replacing key hormones, including oestrogen and progesterone, that the body stops producing in the same amounts during menopause. A lack of these hormones can cause a wide range of menopause symptoms, such as hot flushes, low mood, sleep issues and night sweats (1).

One of the most common worries amongst women starting HRT is weight gain; no doubt, weight can change during menopause, and the timing of the HRT can make it seem like HRT is to blame for the weight gain.

But is this true? To what extent does HRT cause weight gain, or are there other factors?

In this blog we’ll explore the relationship between HRT and weight gain during menopause, as well as other factors affecting weight during this stage of life.

Oestrogen

Oestrogen is the primary female hormone used to regulate the menstrual cycle. Oestrogen also plays a crucial role in supporting bone health and maintaining the body’s temperature and mood. During menopause, the ovaries slow down the production of oestrogen, leading to a significant decrease in oestrogen, and this decline can lead to a range of symptoms experienced during menopause.

So what does oestrogen have to do with HRT and weight?

HRT can give the body small doses of oestrogen, one of the hormones that declines during menopause. This decrease is responsible for menopausal symptoms like hot flushes, mood swings and sleep disturbances. So, by  HRT helping to top up  oestrogen levels, it can help to reduce these symptoms, such as hot flushes and poor sleep. Oestrogen is also vital for bone health and the reducing the risk of osteoporosis (low bone density).

What's the link between oestrogen and weight gain?

Interesting fact - the drop in oestrogen does affect how the body stores fat and how the metabolism functions, which is how weight gain might occur.

As oestrogen levels drop, the body becomes more prone to storing fat around the stomach (2). Losses of oestrogen also reduce muscle mass, which can decrease metabolism. This leads to fewer calories being burned, no matter how much your diet remains the same.

This therefore makes it easier to gain weight and harder to lose weight, showing that weight gain can be mainly linked to hormonal changes rather than directly to HRT.

Progesterone

Progesterone is another important female hormone that's produced after ovulation to help the thickening of the uterus lining. As perimenopause occurs ovulation becomes irregular and eventually stops at menopause, causing progesterone levels to drop. This may contribute towards menopause symptoms - mainly symptoms linked with mood changes and sleep disturbances.

Progesterone and HRT

Some HRT treatments will include oestrogen and progestrone, the progestrone is added to protect the womb lining. This is due to the oestrogen causing the lining of the womb to thicken, which causes an increased risk of womb cancer (7). With the use of progesterone, it counteracts this effect and prevents the excessive thickening of the womb lining, reducing the risk of womb cancer.

Overall, progesterone plays an important role in regulating menstrual cycles and maintaining womb health.

What is the link between progesterone and weight gain?

There is no strong link between progesterone in HRT causing weight gain (3).

Does HRT cause weight gain?

Overall, there is no strong evidence that HRT causes weight gain. Instead, weight gain may be the result of

• Natural ageing - the older we get, the slower our metabolism gets due to natural muscle mass decreasing.

• Hormonal changes - lower levels of oestrogen can affect the storage of fat in the body

• Lifestyle shifts - less physical activity, sleep distribution and not adjusting eating habits accordingly

Could weight gain  be a possible side effect of HRT?

No, weight gain in fact is not a direct side effect of HRT. However, fluid retention is a common side effect, which can cause mild bloating around the stomach, which may appear like weight gain. This is a temporary side effect due to the body adjusting to the new hormone levels (4). If fluid retention and bloating remain persistent, speak with your healthcare professional.

Tips for managing weight gain whilst using HRT

Whilst being on HRT can help to manage menopausal symptoms, individuals may notice changes in their weight. Adopting healthy lifestyle habits can help manage these changes in weight, and support your long term health during this transition.

Balanced diet

Balancing meals with wholegrains, lean proteins, fruits and vegetables, and healthy fats can help you to eat smaller portions that fill you up. This can also help with stabilising blood sugar levels, reducing cravings and reducing the need to snack throughout the day.

Regular exercise

Aim for increased physical activity and decreased sedentary time. The NHS guidelines recommend  150 minutes of moderate intensity activity per week, such as brisk walking. Movement  is an important part of  managing weight and can boost mood also. It’s important to participate in a range of movement, including cardio, strength training and restorative exercise (6,8).

Managing stress

Stress can increase cortisol (the stress hormone) which can increase belly fat and cravings for comfort foods. Taking part in meditation breaks, yoga and seeking support with dietary changes from a Registered Nutritionist or Registered Dietitian can help to ease stress. It’s important you take care of your mental wellbeing.

Enough sleep

Poor sleep can make weight loss harder than it needs to be. Try keeping a regular sleep routine and cut back on caffeine in the evening to support better sleep. It may be worth speaking to your GP if you’re experiencing ongoing sleep disturbances. Check out our blog on the impact of sleep on weight loss at menopause here.

Conclusion

Many women worry that HRT may lead to weight gain, however, there is a lack of strong evidence suggesting HRT causes weight gain. Weight gain whilst taking HRT may be due to the natural hormone changes, changes in metabolism and the process of ageing. Adjusting lifestyle habits, including eating, movement, stress and sleep habits can help with weight management whilst on HRT.

This blog was written by Mia Watkins, a second year Nutrition student at Oxford Brookes University with a strong interest in individual health, particularly how the diet can support long term wellbeing. Find Mia on Instagram @nourishwithmex

References

1. Inform, N. (2022). Hormone replacement therapy (HRT). [online] www.nhsinform.scot. Available at: https://www.nhsinform.scot/tests-and-treatments/medicines-and-medical-aids/types-of-medicine/hormone-replacement-therapy-hrt/.

2. BRITISH MENOPAUSE SOCIETY Tool for clinicians Information for GPs and other health professionals Menopause: Nutrition and Weight Gain. (n.d.). Available at: https://thebms.org.uk/wp-content/uploads/2023/06/19-BMS-TfC-Menopause-Nutrition-and-Weight-Gain-JUNE2023-A.pdf.

3. NHS (2023). Side effects of hormone replacement therapy (HRT). [online] nhs.uk. Available at: https://www.nhs.uk/medicines/hormone-replacement-therapy-hrt/side-effects-of-hormone-replacement-therapy-hrt/

4. Menopause matters (n.d.). Side effects of HRT : Menopause Matters. [online] www.menopausematters.co.uk. Available at: https://www.menopausematters.co.uk/sideeffects.php.

5. Wellbeing of Women (2025). How do I eat well for the menopause? - Wellbeing of Women. [online] Wellbeing of Women. Available at: https://www.wellbeingofwomen.org.uk/health-information/how-do-i-eat-well-for-the-menopause/ [Accessed 23 May 2025].

6. NHS (2024). Physical activity guidelines for older adults. [online] NHS. Available at: https://www.nhs.uk/live-well/exercise/physical-activity-guidelines-older-adults/.

7. NHS (2023b). Types of hormone replacement therapy (HRT). [online] nhs.uk. Available at: https://www.nhs.uk/medicines/hormone-replacement-therapy-hrt/types-of-hormone-replacement-therapy-hrt/.

8. Brown, C. (2024). 10 Benefits of Cardio and Strength Training. [online] Cardio Sports. Available at: https://www.cardiosports.org/10-benefits-of-cardio-and-strength-training/ [Accessed 29 May 2025].