Segesterone Acetate/Ethinyl Estradiol

Limits on what this shows

• Key null findings: None located.
• At-risk subgroups: None established; animal/in vitro data only. No human mitochondrial biopsy or functional-imaging data for this drug or class was found.

Regulatory status

Not addressed in the FDA label.

Population evidence

Fuller KNZ, et al. Oral combined contraceptives induce liver mitochondrial reactive oxygen species and whole-body metabolic adaptations in female mice. J Physiol. 2022. PMID 36326014. Title/indexing confirmed via PubMed search-listing in this project's prior review; full text remained inaccessible this review (repeated HTTP 429/reCAPTCHA).

Mechanism

Systemic estrogen/progestin exposure altering hepatic mitochondrial redox handling (mechanism E). This mouse study used the oral route and an unconfirmed hormone formulation, weakening direct applicability to a vaginally delivered, segesterone-acetate-paired product.

Counter-evidence held on record

Rodent liver model, oral route, hormone formulation not confirmed identical to segesterone acetate/ethinyl estradiol. A dedicated PubMed search this review for "segesterone acetate mitochondria" returned a reCAPTCHA challenge page on every attempt rather than a substantive result; this is disclosed as a tooling limitation, not a confirmed segesterone-specific null, and a revision should re-attempt this query directly. Not evidence that this drug itself burdens mitochondria. It documents an oral-class, animal-only mechanistic signal only; see Overlap map for its mechanistic (not source) relationship to the Oxidative stress entry above.

Limits on what this shows

• Key null findings: None located specific to any ring product.
• At-risk subgroups: None established specific to Annovera.

Regulatory status

Not addressed in the FDA label.

Population evidence

Palan PR, et al. 2010 (PMID 20814444), the same source as the Vitamin E/CoQ10 entry above (see Overlap map): serum total antioxidant capacity significantly lower (P<.05) among contraceptive-user groups versus controls.

Mechanism

Consistent with the vitamin E/CoQ10 finding above, reduced circulating antioxidant reserve under estrogen exposure. No specific oxidative-damage marker (malondialdehyde, F2-isoprostanes) for this drug or class was located.

Counter-evidence held on record

Same single-study limitation as Vitamin E/CoQ10. A dedicated PubMed search this review for "segesterone acetate oxidative stress" returned a reCAPTCHA challenge page on every attempt rather than a substantive result, so this review cannot state whether segesterone-specific oxidative-stress literature exists or not; this is disclosed as a tooling limitation, not a confirmed gap, and a revision should re-attempt this query. Not a basis for general antioxidant-supplement stacking; this describes a group-level difference in a different ring product's users, not a diagnosis of oxidative damage in any individual Annovera user.

Limits on what this shows

• Key null findings: Kamyab 1980 itself reports the rise attenuates after roughly 48 months, suggesting hepatic adaptation rather than progressive accumulation. No study located found copper reduced or unchanged in oral-COC users.
• At-risk subgroups: Individuals with known copper-handling disorders (e.g., Wilson disease) warrant individualized counseling. No evidence of copper toxicity from combined hormonal contraceptive use, any route, was located.

Regulatory status

Not addressed in the Annovera FDA label.

Population evidence

Kamyab S, Baghdiantz A, Jenati S. Variations in serum copper and ceruloplasmin activity following a long term intake of combined oral contraceptives in Iranian women. J Endocrinol Invest. 1980;3(2). PMID 7391523: n=104 oral-COC users (3-108 months' use) versus n=24 never-users; serum copper and ceruloplasmin activity significantly higher (P<.005) in 100% of users, 11-175% above control means. Corroborating class-level titles confirmed via PubMed search-listing, not independently re-opened this review: Carruthers ME, et al. 1966 (PMID 5919365); Schenker JG, et al. 1972 (PMID 4362283). A dedicated PubMed search this review for "segesterone acetate copper" returned a genuine, confirmed zero-result page, and a parallel Europe PMC search returned five results, none addressing copper or ceruloplasmin in any way.

Mechanism

Estrogen-receptor-driven induction of hepatic ceruloplasmin (the major copper-transport protein), raising total serum copper through the ceruloplasmin-bound, not free, pool. This is the same hepatic-globulin-induction mechanism family Annovera's own label documents directly for SHBG, cortisol-binding globulin and thyroxine-binding globulin (mechanism F; see Vitamin A below and Overlap map). This is also the mandatory Step 3 Copper category entry for this drug.

Counter-evidence held on record

All supporting primary data are oral-pill studies from decades before this product's 2018 approval, using ethinyl estradiol paired with progestins other than segesterone acetate; no Annovera-specific or segesterone-specific serum copper or ceruloplasmin study exists. Tier C class extrapolation for this drug, carried through the shared ethinyl estradiol component only. Excess/retention-direction finding. Copper supplementation is never indicated by this signal, and this finding should not be used to justify "copper toxicity" or "copper detox" framing.

Limits on what this shows

• Key null findings: No Annovera-specific hemoglobin, ferritin, or quantified blood-loss study was located. The Jain 2016 trial's own PBAC reduction was numerically, not statistically, greater with the ring than an oral comparator (p=0.286), showing non-inferiority to an oral pill, not superiority to no treatment, in that different product's cohort.
• At-risk subgroups: Not established for Annovera specifically. In the class-level trial, benefit concentrated in women with abnormal/heavy uterine bleeding at baseline, a different population than typical Annovera users.

Regulatory status

The Annovera label reports unscheduled bleeding/spotting incidence and amenorrhea rates but does not state a quantified menstrual-blood-loss reduction, hemoglobin change, or anemia finding.

Population evidence

Class-member Tier A evidence: Jain S, et al. A Randomised Controlled Trial Comparing the Efficacy and Side-effects of Intravaginal Ring (NuvaRing) with Combined Oral Hormonal Preparation in Dysfunctional Uterine Bleeding. J Clin Diagn Res. 2016;10(3). PMID 27134949. RCT, n=60, dysfunctional uterine bleeding, significant blood-loss reduction (PBAC score) with the etonogestrel/ethinyl estradiol ring over three months. This trial did not enroll Annovera users and used a different progestin; it is Tier C, not Tier A, for this drug. Annovera's own label data (5-10% unscheduled bleeding per cycle, average <1 day; amenorrhea 3-5% of cycles) is directionally consistent with a net bleeding reduction relative to no contraception but is not itself a quantified blood-loss or iron-balance measurement.

Mechanism

Progestin-dominant endometrial suppression and reduced endometrial vascularity, a recognized class effect of combined hormonal contraception generally, secondarily conserving menstrual iron loss; not a classical absorption or excretion nutrient mechanism, and not specific to segesterone acetate as a molecule.

Counter-evidence held on record

Bounded to class-level mechanism and a different product's bleeding trial; Annovera's own labeled bleeding profile is real but not quantified as a blood-loss or hemoglobin outcome, so this is graded yellow here, not the orange this project assigned to the other ring's own drug-specific bleeding trial. This is a reverse-direction, potentially protective, iron-conserving mechanism, not a depletion signal. Iron supplementation is not indicated by this mechanism, and it should not be read as evidence that Annovera treats or corrects anemia.

Limits on what this shows

• Key null findings: The n=10 oral-route study is itself the key null finding. Separately, drug-specific reassurance from a different organ system: Huang SA, et al. Effects of a One Year Reusable Contraceptive Vaginal Ring on Vaginal Microflora and the Risk of Vaginal Infection. PLoS ONE. 2015. PMID 26267119. This is a pivotal-program study of the Nestorone (segesterone acetate)/ethinyl estradiol ring that became Annovera. Vaginal flora remained H2O2-positive Lactobacillus-dominant throughout the year (76.7% of participants at baseline rising to 90.2% by cycle 13); bacterial vaginosis diagnosed in only 3.3% of participants with no significant change from baseline to cycle 6 or 13; no significant change in vulvovaginal candidiasis or trichomoniasis frequency; Nugent scores remained stable. This is genuine Tier A, drug-specific evidence, but it measures the vaginal, not gut, microbiome, a different organ system, and per this project's established convention is disclosed here as reassuring context, not used to grade Gut microbiome risk.
• At-risk subgroups: None established for gut microbiome specifically.

Regulatory status

Not addressed in the FDA label.

Population evidence

Oral-class gut evidence (title/indexing carried from this project's prior review): "Longitudinal analysis of the impact of oral contraceptive use on the gut microbiome." J Med Microbiol. DOI 10.1099/jmm.0.001512. Longitudinal cohort, n=10, OC formulation unspecified; no significant change in gut microbial diversity or composition after OC initiation, though functional pathway shifts were observed. A second title, "Gut Microbiota Shifts with Lifetime Duration of Oral Contraception Use," was identified but not independently opened. A dedicated PubMed search this review for "segesterone acetate microbiome" and "Annovera vaginal microbiome" both returned substantive results; the latter surfaced a genuinely drug-specific finding, discussed below, that addresses vaginal, not gut, flora.

Mechanism

The "estrobolome" hypothesis (gut bacterial beta-glucuronidase deconjugating and recirculating estrogens, mechanism G) is better established in the direction of the microbiome affecting circulating estrogen than the reverse. This drug's vaginal route delivers no hormone into the gastrointestinal lumen at intake, weakening the mechanistic case for a direct luminal disruption pathway.

Counter-evidence held on record

The only genuinely drug-specific microbiome finding located (Huang 2015) is reassuring but off-target for this category by organ system; the gut-specific evidence remains oral-route, class-level, and mixed/mostly null. Not evidence of "gut damage" from this drug. Popular claims that hormonal contraception broadly "destroys your gut microbiome" are not supported by the null gut study located, and the drug's own vaginal-flora data, while reassuring for that different organ system, cannot be used to make a gut-specific safety claim either.

Limits on what this shows

• Key null findings: No Annovera-specific hemoglobin or hematocrit figures were accessible in this review; this quantitative gap is disclosed rather than papered over, and is the reason this entry is not graded above yellow.
• At-risk subgroups: Not established specific to Annovera.

Regulatory status

Not addressed in the FDA label.

Population evidence

Same class-level trial as Iron above (Jain 2016, PMID 27134949): hemoglobin was measured in that trial's cohort, but exact values were not accessible in the material this review could open, and that trial did not enroll Annovera users regardless. Annovera's own 12-month safety trial (Gemzell-Danielsson 2019, PMID 30831102) indexes hematologic laboratory monitoring as a study domain but its full findings could not be opened this review (see Sources).

Mechanism

Secondary to reduced menstrual blood loss (see Iron), not a direct hemodynamic or pulmonary oxygen-delivery mechanism. This drug's labeled cardiovascular risk profile (the boxed warning on cigarette smoking and cardiovascular events) is deliberately not filed here: that is the drug's own known clinical risk category, not a nutrient-style oxygen-delivery deficiency (Hard Rule 2).

Counter-evidence held on record

Could not independently verify hemoglobin magnitude for either the class-level trial or Annovera's own safety trial from material accessible this review. Graded yellow, not orange, because no Tier A source with Annovera specifically in the cohort and a reported hemoglobin/hematocrit result was located. Do not read this as evidence Annovera corrects anemia in general users. It reflects an unconfirmed, class-level, mechanistically plausible signal, not a basis for using this drug as an anemia treatment.