IGF-1 Levels: What They Mean for Health, Muscle, and Aging

When you hear IGF-1 levels, Insulin-like Growth Factor 1 is a hormone your liver makes in response to growth hormone, playing a key role in tissue repair, muscle growth, and metabolism. Also known as somatomedin C, it’s not just for kids—it keeps working in adults to help maintain muscle, bone density, and cell function. Low IGF-1 can mean muscle loss, fatigue, or even slower healing after injury. High levels? They might link to faster aging or higher cancer risk in some cases. It’s not a simple good-or-bad number—it’s a signal your body uses to talk about growth, repair, and balance.

IGF-1 levels don’t exist in a vacuum. They’re tied to growth hormone, the hormone released by your pituitary gland that tells your liver to make IGF-1. If your growth hormone drops—as it often does with age—IGF-1 follows. That’s why older adults often see lower IGF-1. But it’s not just aging. Nutrition matters. If you’re not eating enough protein or calories, your body won’t produce much IGF-1. On the flip side, excess sugar and processed carbs can throw off the balance, making IGF-1 too high, which may speed up cell aging. Then there’s muscle growth, a process directly influenced by IGF-1, which helps repair and build muscle fibers after exercise. Athletes and lifters often track it, but so should anyone concerned about staying strong as they get older.

What you’ll find in the posts below isn’t a single answer to "what should my IGF-1 be?"—it’s a collection of real, practical insights. You’ll see how doctors interpret these numbers, how diet and lifestyle shift them, and how they connect to other health markers like insulin sensitivity, thyroid function, and even sleep quality. Some posts dive into how certain medications or supplements affect IGF-1. Others show how it plays into chronic conditions like diabetes or heart disease. This isn’t about chasing high numbers for muscle gain—it’s about understanding what your body’s IGF-1 is telling you, and how to respond in a smart, safe way.