Why IGF-1 Levels Don't Matter

At least not that much

Author

Hunter Williams
February 04, 2025

Today, I want to dive into an important topic:

Why testing your IGF-1 levels doesn't really matter when it comes to optimizing growth hormone.

This was also the subject of my YouTube video that was released today.

How People Use IGF-1 to Assess Growth Hormone Deficiency

One of the biggest misconceptions I see in the peptide and biohacking community is using IGF-1 levels as a primary marker for whether or not someone needs growth hormone peptides or HGH therapy.

It’s common for people to think, “If my IGF-1 is low, I need HGH or peptides. If it’s high, I’m good.” 

It makes sense on paper; I even fell into this trap in my younger years.

But by the end of this email, you’ll understand why this is not as cut and dry as it seems.

Yes, IGF-1 levels do decline naturally with age—after 30, levels drop by about 15% per decade—which means that most people can benefit from optimizing growth hormone.

However, IGF-1 testing is not a perfect indicator of whether you need peptides or HGH.

Here’s why:

The Major Flaws in Using IGF-1 as a Primary Growth Hormone Marker

  1. IGF-1 Levels Are Highly Variable

    • IGF-1 fluctuates throughout the day and can be affected by sleep, diet, stress, and training levels.

    • If you test at different times of the day or after a night of poor sleep, your IGF-1 levels can vary wildly.

  2. Receptor Sensitivity Matters More Than Total Levels

    • As we age, IGF-1 receptors become less sensitive, meaning even with the same IGF-1 levels, the body might not respond as well.

    • This is why an older person might need higher HGH or peptide doses to get the same benefits as a younger person.

  3. Peptides and HGH Use Aren’t Always Reflected in IGF-1 Tests

    • Many people assume that taking HGH or peptides will always result in a significant IGF-1 increase. That’s not necessarily true.

    • The effectiveness of peptides like Tesamorelin, Ipamorelin, or CJC-1295 depends on your individual physiology, liver function, and receptor sensitivity—not just IGF-1 bloodwork.

So what do we do then?

The Real Signs That You May Need Growth Hormone Peptides

Instead of obsessing over a single IGF-1 number, symptoms are a much better way to determine whether growth hormone optimization is right for you.

Ask yourself these questions:

1. Physical Health & Fitness

  • Have you lost muscle mass or strength despite consistent weight training?

  • Are your workouts less effective, and do you recover slower than before?

2. Body Fat & Metabolism

  • Have you noticed an increase in visceral fat, particularly around the abdomen?

  • Is it more challenging to lose fat, even with proper diet and exercise?

3. Energy & Exercise Capacity

  • Do you feel a persistent lack of energy or fatigue, even after a whole night’s sleep?

  • Have you experienced a decrease in endurance or stamina?

4. Recovery & Injury Healing

  • Are you taking longer to recover from injuries, sprains, or muscle soreness?

  • Do you have joint pain or stiffness that affects mobility?

5. Sleep & Cognitive Function

  • Do you have trouble falling asleep or staying asleep throughout the night?

  • Are you experiencing brain fog, memory issues, or lack of focus?

  • Have you noticed mood swings, irritability, or increased anxiety?

6. Aging & Longevity

  • Do you feel like you’re aging faster than you should?

  • Are your skin, hair, and nails thinning, dry, or losing elasticity?

7. Immune System & Health Resilience

  • Do you get sick more often or feel like your immune system is weaker than before?

  • Have you struggled with slow wound healing or recovery from illness?

If you answered YES to at least three or more of these questions, you may be a strong candidate for growth hormone optimization regardless of what your IGF-1 blood test says.

What You Should Do Instead of Just Testing IGF-1

Since IGF-1 levels aren’t a perfect indicator, here’s a better way to determine whether growth hormone peptides or HGH are right for you:

  1. Track your symptoms, not just your labs.

    • If you’re struggling with energy, sleep, muscle loss, or fat gain, peptides might help—even if your IGF-1 is “normal.”

  2. Optimize your lifestyle first.

    • Ensure your diet, hormones, sleep, stress management, and training are dialed in. Peptides and HGH will only work well if your foundation is solid.

  3. Experiment with a growth hormone peptide and track the results.

    • The best way to see if something works for you is to try it and measure your progress.

    • The top peptides I recommend for growth hormone optimization include:

      • Tesamorelin – The strongest for IGF-1 boost and fat loss

      • Ipamorelin – Best for sleep and recovery

Final Thoughts: Should You Even Track IGF-1?

Yes, IGF-1 bloodwork is still useful, but it shouldn’t be the only thing you rely on.

I personally test my IGF-1 levels every time I get labs done, but I also recognize that they are just one piece of the puzzle.

I’ve seen my IGF-1 range from 180 to 370 on the same exact growth hormone protocol of 2iu per day.

If I only relied on the number to determine my peptide/hgh use, I’d be making a mistake.

Instead, I focus on how I feel, my sleep, my body composition, and my energy levels.

Growth hormone optimization should always be about symptom resolution and performance enhancement, not just chasing arbitrary numbers on a lab test.

Remember, treat symptoms, NOT lab work.

Best,

Hunter