Insulin: The Master Hormone That Affects All Other Hormones

If you’ve ever felt like your body is working against you—your cravings are out of control, your sleep is a mess, your mood is unpredictable, and your period shows up whenever it feels like it—you’re not imagining things. These aren’t random issues. They’re connected. And at the root of it all, there’s one hormone quietly pulling the strings: insulin.

We usually only hear about insulin in the context of diabetes, but the truth is, insulin does way more than regulate blood sugar. It’s the master hormone—the one that sets the stage for how almost every other hormone in your body functions. Think of it like the foundation of a house. If the foundation is unstable, everything built on top of it starts to crack. That’s exactly what happens when insulin is too high, too often.

And the problem? Our modern lifestyle makes it almost impossible to keep insulin in check. Starches, sugar, excess dairy, late-night snacks, stress, snacking all day—it all adds up. And when insulin is chronically elevated, the entire hormonal symphony gets thrown off tune.

Now let’s talk about something you’ve probably seen online at least a dozen times this week:
“Balance your hormones.”

It’s the wellness industry’s favorite buzz phrase. You’re told you can balance your hormones with a special tea, a supplement stack, a grounding mat, a crystal-infused bath, a green juice, or more sunshine. But here’s the thing—you cannot balance your hormones if your insulin is high. Period. Full stop.

There is no herb, no adaptogen, no supplement, no essential oil that’s going to fix your hormones if insulin is running the show. Stop wasting your money on gimmicks. You don’t need another detox kit. You need to lower your insulin. And that starts with changing the way you eat.

1. Appetite Hormones: GLP-1, Ghrelin, and Leptin

GLP-1 is having its moment in the spotlight, thanks to blockbuster weight-loss drugs like Ozempic and Wegovy. But this hormone exists naturally in your body, and it plays a big role in helping you feel full after a meal. What most people don’t realize? One of the best ways to boost your natural GLP-1 is by lowering insulin.

High insulin levels reduce GLP-1 activity and make it harder to feel satisfied, which means you end up eating more. It also creates resistance to leptin, your “I’m full” signal, and exaggerates the effects of ghrelin, your “I’m starving” hormone. The result? Cravings, overeating, and feeling like you’re never really satisfied—even after a big meal.

If you’ve ever asked yourself, Why am I hungry again already?—insulin may be the answer.

2. Mood and Sleep Hormones: Dopamine, Serotonin, and Melatonin

Insulin also affects how you feel mentally and emotionally—not just physically.

• Dopamine, the feel-good chemical tied to motivation and reward, is directly influenced by insulin. Chronically high insulin can mess with dopamine turnover, leading to disrupted reward signaling which increases cravings for sugar and starch, mood swings, and depression.

• Serotonin, the hormone tied to mood, calmness, and emotional stability, is also regulated by insulin. Insulin affects how serotonin is produced, transported, and metabolized. When insulin is high, serotonin balance gets thrown off, which can lead to irritability, low mood, and anxiety.

• Melatonin, your sleep hormone, runs on the opposite schedule of insulin. It naturally rises at night to help you fall asleep—right when insulin should be dropping because you’re not eating while you’re asleep. But here’s the catch: even if you stop eating in the evening, if your insulin is chronically elevated during the day, your liver may not be able to clear it overnight. That means insulin stays high when it should be low, and melatonin gets suppressed. The result? You might struggle to fall asleep, stay asleep, or reach that deep, restorative kind of rest your body actually needs.

3. Aldosterone: The Water Retention Hormone

Aldosterone is the hormone that controls how much sodium and water your body holds onto—and insulin has a direct impact on it. When insulin is high, it signals your body to retain more sodium and water, which leads to bloating, puffiness, and even noticeable weight fluctuations. I’ve lived this myself. I could swing 5 to 7 pounds in a matter of days—even when I wasn’t near my cycle—just based on what I was eating. That’s why high-insulin days often leave you feeling heavy, swollen, and inflamed, even if you haven’t eaten more calories or salt.

4. Thyroid Hormones: TSH, T3, and T4

So many people—especially women with PCOS—are diagnosed with thyroid issues, but what if the thyroid isn’t the true root cause?

High insulin interferes with how the thyroid functions on multiple levels:

• It affects TSH, the signal from your brain to your thyroid.

• It disrupts conversion of T4 (inactive) to T3 (active).

• It increases reverse T3, which blocks T3 from working properly.

• It can even trigger autoimmune reactions like Hashimoto’s.

Here’s the kicker: in many cases, it’s not that thyroid issues cause insulin resistance—it’s that insulin resistance causes the thyroid to struggle. A diagnosis of hypothyroidism may actually be the result of chronically elevated insulin levels, not a true thyroid disorder. And if that’s the case, no amount of thyroid medication will fix the root issue.

This happened to me. When I was being diagnosed with PCOS, my doctor ran tons of labs—cholesterol, thyroid hormones, A1c… everything except insulin. My TSH came back elevated, which typically signals hypothyroidism, so they handed me a prescription for Synthroid and sent me on my way. No questions asked. No digging deeper.

I took it for a month, but I didn’t feel right on it—so I stopped. And instead, I focused on lowering my insulin. Once I got my insulin under control, my thyroid levels normalized—and they’ve stayed normal ever since. I’ve never needed thyroid medication again.

It’s honestly heartbreaking how often the root cause gets ignored in medicine. So many people are being medicated for symptoms without anyone asking, why is the thyroid struggling in the first place?

5. Reproductive Hormones: Estrogen, Progesterone, and Testosterone

Insulin has a massive impact on reproductive hormones—for both women and men.

In women, high insulin levels stimulate the ovaries to produce excess testosterone, leading to irregular periods, acne, hair growth in unwanted places, and even infertility (hello, PCOS). It also lowers sex hormone binding globulin (SHBG), which means more free testosterone and estrogen are floating around.

But there’s more—high estrogen levels, especially when unopposed by progesterone, are associated with increased breast cancer risk. And insulin is a known driver of estrogen dominance.

In men, high insulin can contribute to low testosterone, fatigue, belly fat, and even infertility.

Bottom line: reproductive hormone balance doesn’t happen without insulin balance.

6. Growth Hormones: IGF-1 and mTOR

Insulin doesn’t just help you grow during puberty. It continues to activate growth pathways throughout life—especially IGF-1 (Insulin-like Growth Factor 1) and mTOR, a key cellular growth switch.

These pathways are essential. We need them for tissue growth, healing, and repair. But when insulin is constantly elevated, they stay permanently switched on—and that can be a problem.

• Chronically elevated IGF-1 is strongly associated with increased cancer risk.

• Constant activation of mTOR is linked to accelerated aging, cellular stress, and breakdown.

These growth pathways are supposed to turn on when needed—not be running 24/7. Insulin is meant to help activate them during periods of growth, healing, or muscle repair. But when insulin is always high, these systems go into overdrive, and over time, that takes a serious toll on your long-term health.

This is also one big reason why dairy can be so problematic.
Milk naturally contains IGF-1, which means every time you drink milk, you’re literally telling your body to grow. That might sound like a good thing—until you remember the biological purpose of milk: to support rapid growth in a newborn. It does that by delivering IGF-1 to elevate the newborn’s IGF-1 levels and stimulate growth.

But most of us aren’t growing anymore, at least vertically. In fact, constantly triggering growth pathways in adulthood isn’t helpful—it’s harmful. Chronically elevating IGF-1 through consumption of dairy can increase your risk of unwanted growth, like cysts, tumors, and even cancer.

Milk is for growth. But if you’re not a growing baby calf, it might be time to rethink the idea that it’s a “health food.”

Bottom Line: Want to Balance Your Hormones? Start with Insulin.

When people talk about “balancing hormones,” they’re usually thinking about fixing one specific issue—better sleep, fewer mood swings, a regular cycle, or help with weight loss. But the truth is, you can’t truly balance your hormones without first addressing insulin.

Insulin is the master hormone—the one calling the shots behind the scenes. If it’s high all the time (which is more common than most people realize), every other hormone system gets thrown off. From cravings and sleep, to thyroid, fertility, and even cancer risk—it all traces back to insulin.

And the best way to lower insulin?
Not another crash diet.
Not more supplements.
Not guessing in the dark.

The best way to lower insulin is by following A Low Insulin Lifestyle—a way of eating, moving, and living that’s designed to keep insulin stable and allow your hormones to finally do what they were meant to do.

It’s not about perfection. It’s about creating a foundation where your body can thrive. Balance insulin—and everything else starts to fall into place.

References

Harikrishna A, et al. The impact of obesity and insulin resistance on thyroid cancer: A systematic review. Maturitas. 2019. Read more

Colussi G, et al. Insulin resistance and hyperinsulinemia are related to plasma aldosterone levels in hypertensive patients. Diabetes Care. 2007. Read more

Zhang AMY, et al. Hyperinsulinemia in Obesity, Inflammation, and Cancer. Diabetes Metab J. 2021. Read more

Greenwood EA, et al; Eunice Kennedy Shriver National Institute of Child Health and Human Development Reproductive Medicine Network. Insulin resistance is associated with depression risk in polycystic ovary syndrome. Fertil Steril. 2018. Read more

Stenvers DJ, et al. Circadian clocks and insulin resistance. Nat Rev Endocrinol. 2019. Read more

Verdich C, et al. The role of postprandial releases of insulin and incretin hormones in meal-induced satiety–effect of obesity and weight reduction. Int J Obes Relat Metab Disord. 2001. Read more