What is Androgen Receptor Sensitivity Testing and Why it Matters

If you’ve ever wondered why two men with the same testosterone levels can feel completely different, you’re not alone. One man might feel energized, confident, and strong, while the other struggles with fatigue, low mood, and sluggish recovery. The difference isn’t always about testosterone levels—it’s about how your body responds to testosterone. That’s where the androgen receptor (AR) comes in.

At the heart of your testosterone response are two key variables: AR Sensitivity and AR Density. These factors determine how efficiently your body uses testosterone, and understanding them could be the missing piece in your hormone health puzzle.

AR Sensitivity: The DNA Blueprint

AR Sensitivity refers to how responsive your androgen receptors are to testosterone. This sensitivity is determined by your genetics—specifically, the number of CAG repeats in the AR gene. Fewer repeats mean higher sensitivity. In simple terms: your cells respond more powerfully to the same amount of testosterone.

Think of AR Sensitivity like the brightness of a lightbulb. The manufacturer (your DNA) sets the brightness, and it stays the same throughout your life. If your bulbs are naturally brighter, you’ll get more light (or testosterone effect) even with the same wattage.

Men with shorter CAG repeats often report:

• Higher energy levels

• Faster recovery

• Stable mood and motivation

• Greater ease building muscle

Those with longer CAG repeats may experience:

• Fatigue and sluggishness

• Slower recovery from workouts

• Trouble maintaining lean mass

• Low drive, despite “normal” T levels
  

AR Density: The Lifestyle Lever

AR Density, on the other hand, refers to how many androgen receptors you have in your tissues. Unlike sensitivity, density can change over time based on factors like training, inflammation, medications, hormone exposure, and aging.

Returning to our light analogy, AR Density is like the number of lightbulbs installed. More bulbs mean more light, even if each one isn’t ultra-bright. And the good news? This is the piece you can influence through lifestyle choices.

For example, resistance training and proper hormone support can increase AR density, amplifying your testosterone response without necessarily changing your T levels.

Why This Matters

Standard lab tests only tell you how much testosterone is in your blood. They don’t tell you how well your body is using it. That’s why some men with “normal” lab results still feel off. Your AR-CAG repeat length could hold the answer.

Understanding both your sensitivity (the brightness of each bulb) and density (how many bulbs are installed) allows for a more accurate, personalized approach to hormone optimization

Start Your Marek Health Journey

Marek Health is leading the way in personalized hormone care by offering the only direct-to-consumer AR Sensitivity test. This genetic test reveals your CAG repeat length—giving you insight into how your body actually uses testosterone.

If you’re tired of chasing lab numbers that don’t match how you feel, it might be time to look deeper. With Marek’s test, you’ll get answers rooted in your DNA and a path toward real, individualized optimization.

Understanding your testosterone levels is just the beginning. Unlock the deeper story written in your DNA by exploring your androgen receptor sensitivity—a key to true hormone optimization.

After learning about AR Sensitivity and Density, you’re now equipped with insights most standard labs overlook to get the most out of your Marek Health diagnostic labs, whether you’re optimizing performance, energy, mood, or long-term wellness.

Ready to take action?
Book your free discovery call today and get matched with a care team that understands your biology, your goals, and your potential.

Disclaimer: This blog post is intended for informational purposes only and should not be considered medical advice. Consult with a healthcare professional before making any changes to your wellness routine.