Regardless, even that study you shared still states "Findings from the current study indicate that testosterone supplementation suppresses hepcidin in healthy human adults". So it is to be expected that ferritin also drops.
You say healthy men on t-therapy, with the current epidemic of secondary hypogonadism, most people getting on t are not too healthy, years of hypogonadism wreaks havoc in many cases.
As Funk said, there seems to also be many cases where the ferritin came back up eventually, one i know personally did say he took supplemental iron on top of red meat. Then again i know someone who's ferritin rose back on it's own, as did his hematocrit creep back down, makes sense. The latter had been on t-therapy for a good six months or so when it balanced and did lower his dose(longer injection frequency) a tiny bit as well.
This was interesting;
"Other possibilities include a direct effect of testosterone on bone morphogenetic protein (BMP)–sons of mother against decapentaplegic (SMAD) signaling (
11) and/or the aromatization of testosterone to estradiol, which suppresses hepcidin transcription (
22,
23)."
chatgpt:
Key study: direct suppression of hepcidin by estradiol
A 2012 paper in The Endocrine Society’s journal
Endocrinology showed that
17β-estradiol (E2) directly reduced hepcidin transcription in liver cells. Researchers found:
- Lower hepcidin mRNA in human hepatocyte cell lines after estradiol exposure
- Suppression was blocked by an estrogen receptor antagonist
- Estradiol acted through an estrogen response element (ERE) in the hepcidin promoter
- Estradiol also reduced hepatic hepcidin expression in mice
Mechanistically, the paper proposed:
E2→ER→↓HAMP (hepcidin) transcriptionE2 \rightarrow ER \rightarrow \downarrow HAMP\,(hepcidin)\ transcriptionE2→ER→↓HAMP(hepcidin) transcription
where:
- E2E2E2 = estradiol
- ERERER = estrogen receptor
- HAMP = the hepcidin gene
The authors explicitly concluded that estradiol suppresses hepcidin to increase iron availability.
