Leptin: The “I’m Full” Hormone That Could Be Sabotaging Your Weight Loss in Perimenopause

If you’re eating clean, working out, and still struggling to lose weight in your 40s and 50s, there’s a little-known hormone you need to know about: leptin.

Leptin is often called your “I’m full” hormone because it tells your brain when you’ve had enough to eat. Sounds simple, right? But during perimenopause, when hormones are already fluctuating, leptin’s signals can get muffled or ignored, leaving you stuck in a cycle of cravings, stubborn belly fat, and frustration.

Here’s why leptin matters more than ever for midlife women (and what you can do to reset it).

What Is Leptin and Why Should You Care?

Leptin is made by your fat cells, and its job is to:

• Signal your brain when you’ve had enough food

• Regulate your metabolism and energy balance

• Help your body decide whether to burn or store fat

But here’s the tricky part… when leptin levels stay high for too long (which often happens if you’re carrying extra weight or eating a highly processed diet), your brain stops responding. This is called leptin resistance.

It’s like your brain has put earplugs in, it can’t hear leptin’s “I’m full” message anymore. The result?

• Constant hunger or cravings

• Slowed metabolism

• Difficulty losing weight even on a calorie deficit

Sound familiar?

Why Perimenopause Makes Leptin Resistance Worse

During perimenopause, declining estrogen levels can change how your body processes leptin. Estrogen normally helps your brain stay sensitive to leptin’s signals. So when estrogen drops, your brain may stop responding effectively, leading to:

• Midsection weight gain

• Stronger sugar or carb cravings

• Feeling hungry soon after eating

Combine that with poor sleep (another leptin disruptor) and higher stress hormones like cortisol, and you’ve got the perfect storm for weight struggles.

How to Reset Leptin Naturally

The good news? You can support your body in responding to leptin again with some simple, science-backed shifts:

• Prioritize protein at every meal: Protein helps you feel full longer and reduces cravings.

• Stop snacking all day: Constant eating keeps leptin levels high. Aim for proper meals with breaks in between to give your hormones a chance to reset.

• Get 7-8 hours of sleep: Poor sleep increases hunger hormones (ghrelin) and reduces leptin sensitivity.

• Strength train 3-4 times a week: Building muscle improves your body’s hormone sensitivity, including leptin.

• Manage stress: High cortisol blocks leptin’s effects. Meditation, breathwork, or even a 10-minute walk outdoors can make a big difference.

The Bottom Line

If your body feels stuck, it’s not because you lack willpower. It’s because your hormones, including leptin, aren’t sending the right signals anymore.