Why Do Hormonal Imbalances Make Me Gain Weight?

Medically reviewed by Dr. Stacy Hengisman MD and Felice Ramallo MSRD.

We’ve talked about things like how to prioritize your hormonal health, why exercise can be beneficial for it, as well as the different types of individual hormonal imbalances many women struggle with, but what we haven’t spoken about is why a hormonal imbalance can often impact your weight. Some feel like this is a ‘taboo’ topic - afterall, we know relying on BMI as a “single measure of health” is certainly not perfect and misses much of the bigger picture - while truly the number on the scale is zero reflection of your worth. With that said, no one can dispute the fact that gaining weight, without intention, can be confusing  and commonly, extremely emotionally distressing. So if you have a hormonal imbalance, or you’re wondering if you might have one, and you’ve noticed significant changes in your weight without a reason you can point to, then you might find this article insightful. We’ll be diving into: 

  • What counts as a hormonal imbalance 
  • Which hormonal imbalances are linked to weight gain
  • What they are, their symptoms, and why they cause weight gain

  • Solutions for treating a hormonal imbalance 

Let’s dive right in. 

What counts as a hormonal imbalance 

Broadly speaking, a hormonal imbalance is what “happens when you have too much or too little of one or more hormones - your body’s chemical messengers.”   A hormonal imbalance can be inconvenient at best, and even life-changing at worst, as symptoms can crop up that are extremely unpleasant and it can be difficult to pin down why. 

How to know if you have a hormonal imbalance? 

A hormonal imbalance needs to be diagnosed by a doctor. 

For most women, what prompts them to see a doctor in order to diagnose an imbalance is one or more symptoms that bother them. 

Common symptoms of a potential hormonal imbalance include:

  • Hair loss/thinning hair 
  • Fatigue 
  • Sudden weight gain

  • Dry skin
  • Headaches
  • Loss of libido

  • Irregular periods
  • Chronic cystic acne 

Because we produce so many hormones, signs of a hormonal imbalance can be numerous, and manifest in different  ways, depending on the person. 

That’s why if you have new, or recurring, symptoms that bother you, you should first and foremost make an appointment with your  physician. From there, they will likely listen to your symptoms and based on this information - as well as medical history, family history, and lifestyle - they will order specific tests to try and figure out what may be the cause behind your symptoms. 

Hormonal imbalances linked to weight gain 

  • PCOS

What is it: PCOS is a reproductive disorder that is characterized by androgen dominance, irregular periods and sometimes insulin resistance. 

Symptoms: Common symptoms of PCOS include: hair loss (otherwise known as androgen alopecia), hormonal acne (usually cystic), weight gain, irregular or absent menstrual periods, heavy periods when they do occur, and hirsutism (excess hair growth on the body, in particular  face, lower abdomen, back, and chest). 

Link to weight gain: The CDC notes that women with PCOS are also often insulin resistant, and have a slightly higher level of androgens than women without PCOS. Interestingly, insulin resistance “happens when cells in your muscles, fat, and liver don’t respond as they should to insulin, a hormone your pancreas makes that’s essential for life and regulating blood glucose (sugar) levels” - as a result, the body needs to make more insulin to maintain regular blood sugar levels, eventually leading to the overproduction of insulin. Here’s the thing though: according to Cleveland Clinic, insulin resistance is thought to be related to obesity. So even though it’s not clear whether PCOS is a “direct cause” of weight gain, there does seem to be a link between the two; more research is needed to understand how weight gain, androgens, and insulin resistance all work together to manifest PCOS symptoms. 


What is it: hypothyroidism is where your thyroid doesn’t produce enough thyroid hormone. This is usually known as having an ‘underactive’ thyroid.

Symptoms: there are many symptoms of an underactive thyroid, some of which may include, tiredness, dry skin, muscle weakness, coarse hair and skin, weight gain, thinning hair, menstrual cycles that differ from the normal, constipation, and hoarse voice. 

Link to weight gain: hypothyroidism does seem to be linked to weight gain in that weight gain is a commonly known symptom of hypothyroidism. Weight gain is modest, typically around 5 to 10 pounds, according to the American Thyroid Association. The reason for this weight gain is not well understood, though there is conjecture that it could be an interplay of how the thyroid influences metabolism, and the fact that people with hypothyroidism often experience fatigue or tiredness. 


Treatments for a hormonal imbalance 

PCOS: treatment for PCOS can encompass everything from medication (such as birth control and metformin) to lifestyle changes that include diet and exercise, to supplements, and beyond.

Hypothyroidism: daily hormone replacement tablets are usually taken; getting the dosing right can be a process in which you will be put on a lower dose at first, undergo testing, and the dose will be amended as you and your doctor find the right dosage amount over time.