Medroxyprogesterone

Limits on what this shows

• Null findings: None specific to mitochondrial endpoints located for MPA in this review; the broader vitamin/trace-mineral panel study did not assess mitochondrial markers. [5]
• At-risk subgroups: Not established in humans; if the brain-mitochondrial-antagonism mechanism translates clinically, postmenopausal women using MPA-containing hormone therapy (where it blunts, rather than adds to, estrogen's neuro-mitochondrial signal) would be the theoretical population of interest.

Regulatory status

Not addressed in the FDA label.

Population evidence

None in humans. Tier B only: an animal/mechanistic study found MPA antagonizes estrogen's upregulation of brain mitochondrial function; separate in vitro studies in glioma and breast tumor cell lines report MPA effects on mitochondrial parameters at pharmacologic, supraphysiologic (oncology-range) concentrations. [17,19,20]

Mechanism

Present (mechanism class E): MPA directly opposes estrogen-driven mitochondrial biogenesis/function signaling in the brain model; the tumor cell-line studies suggest a direct mitochondrial-toxicity interaction at high concentration, distinct from the brain-estrogen-antagonism mechanism.

Counter-evidence held on record

No human trial has measured mitochondrial function, ATP output, or a validated functional mitochondrial marker in MPA-treated patients; this entry cannot advance beyond mechanism-only until one does. Do not present this as "MPA damages your mitochondria" to a consumer. It is an animal/in vitro signal that estrogen's mitochondrial-supportive signaling is blunted by MPA; it has not been shown to produce a clinical energy or fatigue syndrome in patients.

Limits on what this shows

• Null findings: None specific to systemic oxidative-stress markers located for MPA in typical contraceptive or gynecologic dosing in humans.
• At-risk subgroups: Not established in humans.

Regulatory status

Not addressed in the FDA label.

Population evidence

Tier B only: an experimental spinal-cord-injury animal model reported that MPA (alongside enoxaparin and pentoxifylline, tested separately/in combination) altered lipid peroxidation, PON1 activity, and homocysteine during acute oxidative stress. [18] The brain-mitochondria study above also frames its findings in terms of estrogen's antioxidant signaling being blocked by MPA. [17]

Mechanism

Present (overlaps mechanism class E): redox-marker changes accompanying the mitochondrial-antagonism mechanism above; this review could not open the full text to determine whether MPA's effect in that model was net pro-oxidant or antioxidant, so direction is not asserted here.

Counter-evidence held on record

No human redox-marker study in MPA users (contraceptive or oral dosing) was located despite multiple search phrasings across PubMed; this review's attempt to open the full abstract for the spinal-cord-injury study was blocked by rate limiting (see Sources, entry 18), so the direction and magnitude of the effect are reported at title/listing confidence only. Do not present this as evidence that MPA "causes oxidative stress" or that antioxidant supplementation is indicated; the only direct data are from a non-representative animal injury model, direction unconfirmed from this review's access.

Limits on what this shows

• Null findings: None specific to iron status located; this review's search for a direct DMPA-and-ferritin/hemoglobin study returned no matching result on the phrasing tried.
• At-risk subgroups: None identified for a depletion direction. Adolescents and women with pre-existing menorrhagia would be the group most likely to see a measurable benefit, by the same logic, though this was not directly studied.

Regulatory status

Not addressed in the FDA label as an iron-related effect; amenorrhea and altered bleeding patterns are documented adverse-reaction/expected-effect content.

Population evidence

Tier B/A review-level: a clinical review states "long-term DMPA use reduces menstrual blood loss" [7]; a dedicated bleeding-pattern study of DMPA-SC 104 documents the shift from bleeding/spotting toward amenorrhea over successive injections [8]. Neither directly measures serum ferritin, hemoglobin, or iron stores.

Mechanism

Present (reverse-direction; opposite of mechanism class I): suppression of the hypothalamic-pituitary-ovarian axis produces endometrial atrophy and reduced/absent withdrawal bleeding, lowering the physiologic iron loss that occurs with normal menstruation.

Counter-evidence held on record

This is a mechanism inferred from bleeding-pattern literature, not a directly measured hematologic outcome; DMPA users who continue irregular breakthrough bleeding (common in the first year) would not be expected to see this benefit, and this review found no trial quantifying ferritin or hemoglobin change to confirm the magnitude. This is a protective, not a depleting, direction. It must never be reworded as "Depo-Provera depletes iron" — the documented mechanism runs the opposite way — and it is not a basis for recommending iron supplementation or, conversely, for withholding iron from a patient who is otherwise iron-deficient for unrelated reasons.

Limits on what this shows

• Null findings: A drug-specific study exists but does not test this question: Coombes et al. 2020 incubated MPA itself with human fecal (colonic) microbiota under anaerobic conditions and found MPA is slowly degraded by the microbiota (half-life approximately 644 minutes, versus 28 minutes for progesterone and 240 minutes for levonorgestrel), confirming MPA is exposed to and metabolized by colonic bacteria — but the study measured drug degradation, not any resulting change in bacterial growth, composition, or diversity, so it is not a null (or positive) finding for the compositional question this entry addresses. [25]
• At-risk subgroups: Not established for MPA specifically; no human gut-microbiome data in MPA users of any kind was located in this review.

Regulatory status

Not addressed in the FDA label.

Population evidence

Tier C (class extrapolation; this medication was not in either study's cohort). Hammouda et al. 2023 incubated progesterone, ethinyl estradiol, and L-thyroxine with four isolated gut bacterial species (Bifidobacterium longum, Limosilactobacillus reuteri, Bacteroides fragilis, Escherichia coli): progesterone increased growth of the two Gram-negative species (B. fragilis, E. coli) by 1–2 logs, decreased B. longum growth by roughly 3 logs, decreased biofilm formation in the Gram-positive species while increasing it in the Gram-negative species, and increased adherence of L. reuteri and B. fragilis to intestinal cells. [23] Diviccaro et al. 2022 profiled colonic 16S rRNA microbiota in gonadectomized versus intact rats and found colonic progesterone levels negatively associated with Roseburia abundance, and progesterone-metabolite (dihydroprogesterone/allopregnanolone) levels positively associated with Blautia abundance; this was an endogenous-hormone correlation study, not a drug-administration study. [24]

Mechanism

Present (mechanism class G, microbiome disruption): direct, species-selective effects of a progestogen-class steroid on gut bacterial growth, biofilm formation, and adherence, demonstrated in vitro for progesterone. MPA shares progesterone's steroid nucleus (it is a 17-alpha-hydroxyprogesterone derivative), making a similar direct bacterial interaction plausible, but potency and direction have not been tested for MPA itself.

Counter-evidence held on record

No MPA-specific gut microbiome compositional study exists in either direction. The one MPA-specific gut-microbiota study (Coombes 2020) establishes only that colonic bacteria metabolize MPA, the reverse of the direction this entry addresses, and reports no compositional or growth endpoint. This dossier's vaginal microbiome data on MPA (Yang 2019, Noel-Romas 2020, sources 21–22) is not applicable here; the vaginal and gut microbiomes are anatomically and functionally distinct sites. Do not present this as "Depo-Provera disrupts your gut microbiome." The only direct compositional evidence is for the parent hormone progesterone against isolated bacterial species in vitro, not for MPA itself, and not in a living gut ecosystem or in MPA users. This is class-level mechanistic plausibility, not a demonstrated clinical effect.

Limits on what this shows

• Null findings: None located; this is an unmeasured, inferred direction, not a confirmed null.
• At-risk subgroups: None identified for an impairment direction from this mechanism. Users with persistent breakthrough bleeding rather than amenorrhea would not be expected to see this benefit.

Regulatory status

Not addressed in the FDA label.

Population evidence

Tier B/A review-level, same sources as Iron: reduced menstrual blood loss with long-term DMPA use [7,8]. No direct hemoglobin/hematocrit trial in MPA users was located in this review.

Mechanism

Present (reverse-direction): less menstrual blood loss means less cyclic hemoglobin/iron loss, which would be expected to support, not impair, oxygen-carrying capacity over time in users who become amenorrheic.

Counter-evidence held on record

No trial directly measured hemoglobin or hematocrit change attributable to MPA in this review; this entry is graded on the same underlying mechanism as Iron above (see Overlap map) and should not be read as independent confirmation of it. Reverse-direction, protective mechanism only. This must never be marketed as MPA "boosting energy" or oxygen delivery; it describes the absence of a menstrual-loss burden, nothing more, and is not validated by a direct hematologic trial.

Limits on what this shows

• Null findings: None located.
• At-risk subgroups: Not established.

Regulatory status

Not addressed in the FDA label.

Population evidence

None direct. Tier B only, by extension of the brain-mitochondrial-function study, which did not itself report an ATP-specific endpoint in the search-listing information available to this review. [17]

Mechanism

Present but indirect (extension of mechanism class E): mitochondrial function and ATP synthesis are mechanistically linked, but this review located no study measuring ATP, oxygen consumption rate, or a comparable bioenergetic endpoint specifically for MPA.

Counter-evidence held on record

No direct ATP or bioenergetic measurement exists for MPA in this review; this entry is graded yellow on inference from the mitochondrial-burden entry's mechanism rather than on independent ATP-specific data (see Overlap map), and is the weakest-supported of the five yellow entries in this dossier. Do not present this as "MPA lowers your ATP" or as an explanation for patient-reported fatigue; no bioenergetic marker has actually been measured in MPA users.