InsuranceTom said:

Bloods taken before and after nine months, and the changes are large enough that I want to understand which are cause and which are consequence.

Sex hormone labs after weight loss on the hormone panel — for the men in this thread:

Testosterone: 359 → 559 ng/dL (dramatic improvement!)
Free T: 7.4 → 12.9 ng/dL
Estradiol: 51 → 29 pg/mL
SHBG: 25 → 41 nmol/L

Visceral fat contains aromatase which converts testosterone to estrogen. As you lose visceral fat, this conversion decreases and testosterone naturally rises. I feel 10 years younger.

PurityPaulOR said:

Sex hormone labs after weight loss on the hormone panel — for the men in this thread: Testosterone: 359 → 559 ng/dL (dramatic improvement!) Free T:…

Hormone panel changes on the hormone panel — relevant for anyone curious about endocrine effects:

• Testosterone: increased 35% (weight loss reduces aromatase in adipose tissue)
• Estradiol: normalized from elevated baseline
• SHBG: increased appropriately
• Free testosterone: increased 22%
• Cortisol AM: within normal limits, no significant change

My reproductive endocrinologist says the testosterone improvement alone could explain the energy and mood benefits I've experienced.

InsuranceTom said:

Bloods taken before and after nine months, and the changes are large enough that I want to understand which are cause and which are consequence.

Mine went the same way, slower. The detail I would add is minor and it is already implied above.

Adding the clinical framing, because it changes how the question reads.

HPA axis assessment on the hormone panel: rarely ordered but informative for understanding the stress-metabolism connection:

4-point salivary cortisol:

• Morning: 18 ng/mL → 12 ng/mL (improved)
• Noon: 8 ng/mL → 5 ng/mL
• Evening: 4 ng/mL → 2 ng/mL
• Night: 2 ng/mL → 1 ng/mL

The cortisol curve is normalizing — less flat, better diurnal variation. Reduced visceral fat = reduced cortisol overproduction. The metabolic benefits cascade into stress hormone regulation.