SHBG: The Overlooked Number That Changes Everything About Testosterone

2 min read

8/13/26

Key Takeaways

SHBG, produced in the liver, regulates how much of your sex hormone circulates free and active.
High insulin tends to suppress SHBG; thyroid changes, estrogen, certain medications, and TRT all move it too.
That's why Rythm measures SHBG and albumin alongside total testosterone to calculate free testosterone.

What Moves SHBG Up or Down

Higher SHBG often travels with lower insulin levels, lower body fat, higher-estrogen states, certain medications, or thyroid changes. Lower SHBG is common with insulin resistance, where high insulin suppresses its production in the liver. Because of that, SHBG doubles as a quiet metabolic window not just a hormone statistic.

SHBG on TRT and HRT

TRT often lowers SHBG meaning higher free testosterone and less total testosterone needed to hit targets, with the trade-off of bigger free-T fluctuations and estradiol spikes. For women, estrogen strongly influences SHBG: higher estrogen (including hormone therapy) can raise it, while declining estrogen in perimenopause and menopause can lower it.

How to Use It

Read SHBG together with your other hormone markers, your clinical context, and — above all — the trend. On a connected panel like Rythm's, an SHBG shift is a clue with context attached, rather than a mystery number on its own.

Frequently Asked Questions

How is Rythm different?

Most blood testing companies charge $500 or more for a single test per biomarker, providing only a one-time snapshot that doesn’t capture your long-term health trends or reflect your true baseline. This approach can lead to missed patterns or even misdiagnoses due to limited data. Rythm takes a different approach, using monthly tracking to build a detailed picture of your health over time. This allows for more accurate insights, better optimization, and a clearer understanding of how your body is evolving.

Does Rythm help me improve?

Rythm provides actionable suggestions and tips to help you optimize each biomarker

Is Rythm HIPAA compliant?

Yes, Rythm is HIPAA compliant. Your data is securely stored and handled in accordance with strict privacy and security standards.

Can I cancel anytime without fees?

Yes, you can cancel anytime without any fees.

Does Rythm accept HSA/FSA payments?

Yes, Rythm is HSA/FSA eligible. You can use your HSA or FSA card at checkout or submit your Rythm receipt to your provider for reimbursement.

How long does it take to get my results?

You will receive your results within 3 business days – as long as it's returned within 7 days of receiving your kit. Delays can occur if you do not send your sample back in time.