One of the most common questions I get is: “If I go on HRT, will it help me lose weight?”
The answer is NO! HRT is not a weight-loss drug.
But it’s also not that simple. To really understand this, we need to look at what happens inside your body during perimenopause and menopause and then how HRT might influence that.
Hormones and Weight Regulation: What Changes in Perimenopause
When your reproductive hormones start declining, it’s not just your periods that change. These hormones run through almost every system in your body, metabolism, appetite, fat storage, sleep, mood, even how your muscles and bones behave.
Here’s the breakdown:
Oestrogen
- Oestrogen is an insulin sensitiser. It helps your cells respond properly to insulin, which means you can move glucose (sugar) out of your blood and into your muscles for fuel.
- When oestrogen drops, your body becomes less sensitive to insulin. That means blood sugar spikes easier, cravings increase, and more of the excess glucose gets stored as fat, especially visceral fat around the belly.
- Oestrogen also influences leptin and ghrelin, the hormones that regulate hunger and fullness. Low oestrogen = disrupted hunger cues = you don’t feel as satisfied after meals.
Progesterone
- Progesterone has a calming, anti-anxiety role in the brain. When it falls, sleep can go out the window and cortisol (the stress hormone) climbs.
- Chronically high cortisol increases appetite and promotes abdominal fat storage.
Testosterone and Androgens
- Women also produce small amounts of testosterone, which supports muscle mass. As this declines, you lose lean tissue faster (sarcopenia).
- Less muscle = lower resting metabolic rate, so you burn fewer calories at rest.
Thyroid Connection
- Fluctuating oestrogen can affect thyroid binding globulin, which can change how much thyroid hormone is available. Sluggish thyroid = slower metabolism, more fatigue.
Where HRT Comes In
Hormone Replacement Therapy is designed to bring oestrogen and progesterone (and sometimes testosterone) back into balance. It can absolutely change the environment your body is operating in:
- Improved insulin sensitivity → makes it easier to manage blood sugar, reducing the “rollercoaster” cravings and fat gain.
- Better sleep quality → restoring progesterone and reducing night sweats/insomnia lowers cortisol. With more rest, your appetite hormones (ghrelin/leptin) rebalance.
- Mood stabilisation → less anxiety, less stress eating.
- Preserved lean mass → with HRT plus strength training, it’s easier to hold onto muscle, which helps your metabolism stay higher.
HRT can create better conditions for weight loss but it doesn’t actually cause fat loss on its own.
Why Some Women Gain Weight on HRT
I’ve seen plenty of women get frustrated when they gain 1 to 3 kg after starting HRT. Yes, it was me too, I gained 2kg in the first 6 weeks. That doesn’t mean it’s failing, usually it’s down to:
- Fluid retention in the early months as your body adjusts.
- Progesterone component (especially oral) which can increase appetite.
- No lifestyle change , if diet, movement, and stress management stay the same, the hormonal shift alone won’t drop weight.
What Really Drives Weight Loss in Perimenopause
Think of HRT as levelling the playing field, not playing the game for you. The levers that still matter most:
Nutrition
- Higher protein intake is important 1.6 to 2 g/kg of body weight. Protein stimulates muscle protein synthesis, keeps lean mass, and regulates appetite hormones.
- Fibre supports gut microbiota, which in turn influences oestrogen metabolism and helps manage cravings and blood sugar. You should aim for 25 to 30g of fiber per day.
Resistance training
- Lifting weights builds and preserves muscle, raising your resting metabolic rate and improving glucose uptake.
Stress management
- Chronically elevated cortisol overrides fat loss, no matter what you’re eating.
Sleep hygiene
- Poor sleep alone can raise ghrelin, lower leptin, and increase cravings by 20 to 30% the next day.
Conclusion
HRT won’t melt fat off you. What it can do is:
- Improve insulin sensitivity
- Stabilise mood
- Support better sleep
- Help you preserve muscle
Those things make it easier for your nutrition and training to work but you still need to put the work in.
So, if you’re considering HRT for weight, know this… it’s a tool, not a solution. The solution is building muscle, eating smart, and managing stress in this new hormonal landscape.
Talk to your GP about your options.
P.S. By the way… if you’re ready to finally learn how to eat, train, and thrive through perimenopause without wasting years on conflicting advice, my Perimenopause Course It dives into hormones, metabolism, and nutrition in a way that actually makes sense. It is fully online and you can work at your own pace. Grab it here: https://www.lifehackcoaching.nz/perimenopause-course
