--- title: The research behind Niyora, graded · Niyora description: Every finding Niyora is built on, in one table: what the study found, how good the evidence really is, and a link to the paper. 26 findings, 8 of them strong. url: https://niyora.com/research/ --- Research # Every study behind Niyora, graded honestly Everything in this app comes from a paper. All 26 of them are here, with what the study found and how good the evidence really is. Some of it is strong. Some of it is thin, and I would rather tell you than quietly leave it out. ## How I grade these Strong A randomized trial, or a review of them. About as close to proof as this field gets. Moderate A big observational study, a cell study, or a review that lines up. A real signal, not a proven cause. Weak Small, mixed, argued over, or borrowed from a related field. It is here because leaving it out would be the dishonest move. I do not write "studies show" without a link. If a finding is a correlation, I say so. [See what nobody has studied yet](https://niyora.com/research/gaps/) [Trials you could join](https://niyora.com/research/trials/) ## What are you here for What is actually happening 5 findings Calcium, magnesium, vitamin D 3 findings Things that were actually tested 2 findings Is it PMS, or something else 4 findings Inflammation and blood sugar 4 findings Stress, your history, and cortisol 2 findings Sleep and your body clock 1 finding Your ovaries and your nerves 2 findings Getting help 3 findings ## What is actually happening What is going on in my brain? Genes, GABA, serotonin, and the add-back studies. This is the best-evidenced part of the whole picture, and the reason none of this is in your head. - strong PMDD Your hormones are completely normal. The difference is how strongly your brain feels the shift. Same hormone levels in women who feel awful vs fine; the difference is brain sensitivity to normal shifts (~56% heritable) [Schmidt/Dubey](https://pmc.ncbi.nlm.nih.gov/articles/PMC10176022/) - strong PMDD The calm chemical your body makes from progesterone drops before your period, and sensitive brains feel that withdrawal. Add-back paradigm ties symptoms to GABA / allopregnanolone (progesterone metabolite) withdrawal ["Genes to GABA" review](https://pmc.ncbi.nlm.nih.gov/articles/PMC10176022/) - strong PMS / PMDD When estrogen dips after you ovulate, serotonin dips with it, and your calm system gets thrown off. Review: luteal estrogen drop lowers serotonin; reduced allopregnanolone sensitivity -> GABA/glutamate imbalance + HPA activation [Zinc/Cu/Mg review](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12647176/) - moderate PMDD A big part of how strongly you feel this is inherited. GWAS: premenstrual symptom heritability ~35-57% [GWAS 2025 preprint](https://www.medrxiv.org/content/10.64898/2025.12.01.25341208.full.pdf) - moderate PMDD Researchers can see the difference in your actual cells and blood flow. Cellular Ca2+/ER-stress + brain-blood-flow studies support the ESC/E(Z) sensitivity finding [ESC/E(Z) follow-ups](https://www.nature.com/articles/s41380-021-01144-8) [What is actually happening in full](https://niyora.com/research/mechanism/) [PMS anxiety](https://niyora.com/pms/anxiety/) ## Calcium, magnesium, vitamin D Do supplements actually help PMS? Three of them have real trial evidence behind them. The quality is not the same for all three, so the grade matters more here than anywhere. - strong PMS Calcium every day, all cycle, is one of the few things with real trial evidence behind it. Calcium ~1000-1200mg/day: 73% fewer symptoms vs 15% placebo (crossover RCT) [Thys-Jacobs RCT](https://pubmed.ncbi.nlm.nih.gov/2656936/) - moderate PMS Magnesium can run low inside your cells even when a blood test looks fine. Cellular (erythrocyte) magnesium lower in PMS even when serum looks normal [PubMed](https://pubmed.ncbi.nlm.nih.gov/3800293/) - moderate PMS If your vitamin D is low, topping it up may ease things, partly through inflammation. Vitamin D RCT: supplementation improved symptoms + inflammation markers (in deficiency) [Vit D RCT](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6797739/) [Calcium, magnesium, vitamin D in full](https://niyora.com/research/micronutrients/) ## Things that were actually tested What can I do in the moment that has real evidence? Small physical things that got measured in a trial, instead of just passed around as advice. - strong Acute stress Cold water on your face resets your whole system in seconds. Cold on the face triggers the diving reflex: slows heart, breaks panic (used in DBT) DBT / diving reflex lit - strong PMS Tensing and releasing your muscles one group at a time measurably eases PMS. Progressive muscle relaxation reduces PMS symptoms (RCT, 2024) [PMR RCT 2024](https://pmc.ncbi.nlm.nih.gov/articles/PMC11993963/) [Things that were actually tested in full](https://niyora.com/research/tools-with-evidence/) [How to calm down fast](https://niyora.com/blog/how-to-calm-down-fast/)[How to process anger](https://niyora.com/blog/how-to-process-anger/) ## Is it PMS, or something else How do I know if this is PMS, PMDD, or something else? Some conditions look like PMS. Some overlap with it. Some just make it worse. Here is what tells them apart. - moderate PMDD + ADHD If you have ADHD, the week before your period can hit focus and motivation harder. That's the dopamine dip, not you slacking. Up to ~46% of women with ADHD report PMDD; dopamine dip is the bridge; adolescent PMS-ADHD OR 2.43 [Dorani 2021 / BJPsych 2025](https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/increased-risk-of-provisional-premenstrual-dysphoric-disorder-pmdd-among-females-with-attentiondeficit-hyperactivity-disorder-adhd-crosssectional-survey-study/CD1DC6B31D4B009AB04F580C1189BC86) - moderate PMDD safety If the heavy feeling never fully lifts after your period, that's worth a proper look. PME (depression/anxiety/bipolar worsening premenstrually) vs true PMDD (clears in follicular phase) [PMDD x bipolar review](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8423998/) - moderate PCOD PCOS and PMS aren't the same thing, but they can feed each other. PCOS doesn't cause classic PMS (needs ovulation) but overlaps: insulin resistance + androgens drive mood/cravings [PubMed Central](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8516319/) - weak PMS Thyroid issues can look like PMS, so they're worth ruling out. Thyroid dysfunction can mimic PMS (1986 finding; 1990 study failed to replicate) [NEJM 1986 / JCEM 1990](https://www.nejm.org/doi/abs/10.1056/NEJM198612043152313) [Is it PMS, or something else in full](https://niyora.com/research/differentials/) [PMS vs PMDD](https://niyora.com/blog/pms-vs-pmdd-whats-the-difference/) ## Inflammation and blood sugar Does what my body is dealing with change how the week goes? Two background loads that track with how rough symptoms get. Most of this is correlation, so read the grades closely. - strong PMS / PMDD Stress and inflammation both feed the premenstrual dip. Review: neuroinflammation + stressors in PMS/PMDD [Neuroinflammation review](https://pmc.ncbi.nlm.nih.gov/articles/PMC11985436/) - moderate PMS Low-grade inflammation tracks with worse weeks. hs-CRP >3 linked to 4 of 5 symptom clusters (SWAN, n≈2,900) [SWAN cohort](https://pubmed.ncbi.nlm.nih.gov/27135720/) - moderate PMS Higher inflammation markers line up with worse symptoms. Cytokine levels track menstrual symptom severity [PubMed](https://pubmed.ncbi.nlm.nih.gov/25035435/) - weak-moderate PMS Eating something steady every few hours keeps your mood from spiking and crashing. Stable blood sugar tracks with steadier mood; PMS linked to glucose/insulin/HOMA-IR differences (mixed) [PubMed](https://pubmed.ncbi.nlm.nih.gov/23875163/) [Inflammation and blood sugar in full](https://niyora.com/research/inflammation-and-blood-sugar/) [PMS overwhelm](https://niyora.com/pms/overwhelm/) ## Stress, your history, and cortisol Why does this hit harder when life has been hard? How your stress system shifts across the cycle, and what early hard experiences seem to do to premenstrual symptoms. - strong PMS / cycle Your stress-hormone response genuinely changes across your cycle. Cortisol / HPA-axis reactivity shifts across menstrual cycle phases (meta-analysis) [HPA meta-analysis](https://www.sciencedirect.com/science/article/abs/pii/S0091302222000218) - moderate PMDD If your body learned early that the world isn't safe, these weeks can land harder. Higher childhood adversity -> stronger premenstrual mood worsening + altered late-luteal cortisol [PubMed Central](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10653441/) [Stress, your history, and cortisol in full](https://niyora.com/research/stress-and-cortisol/) [PMS anxiety](https://niyora.com/pms/anxiety/) ## Sleep and your body clock Why does my sleep fall apart before my period? What is known about melatonin timing and sleep across your cycle. - weak-moderate PMDD Your sleep-timing hormone can run off-schedule before your period. Melatonin rhythm shifts in PMDD; small interventional melatonin studies show benefit [Melatonin studies](https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0051929) [PMS insomnia](https://niyora.com/pms/insomnia/)[How to stop overthinking at night](https://niyora.com/blog/how-to-stop-overthinking-at-night/) ## Your ovaries and your nerves Is there a real link between stress and my ovaries? Your ovaries are wired straight into your nervous system. This research is new, and worth watching. - moderate Reproductive Your ovaries and your nervous system are directly wired together. The ovary is directly wired to the nervous system; nerve signals help regulate ovarian function and fertility decline [UCSF/Science 2025](https://www.ucsf.edu/news/2025/10/430841/why-does-female-fertility-decline-so-fast-key-ovary) - moderate Reproductive Ongoing stress doesn't just sit in your head, it can reach your ovaries. Chronic psychological stress impairs ovarian function via HPA/cortisol pathways (review) [Int J Mol Med 2024](https://pmc.ncbi.nlm.nih.gov/articles/PMC11670866/) [Your ovaries and your nerves in full](https://niyora.com/research/ovaries-and-nerves/) [Your ovaries and your nervous system](https://niyora.com/blog/ovaries-nervous-system/) ## Getting help What can be treated, and why do so many of us wait? The clinical references on what is treatable, plus the research on why women wait years before bringing it up. - moderate PMS Premenstrual symptoms are a recognized medical condition, not something you're imagining. Clinical overview of PMS: definition, prevalence, diagnostic criteria, management (StatPearls) StatPearls / NCBI Bookshelf - moderate Mental health Most women wait a long time before asking for help with this, and that's not a personal failing. Study of whether/why women seek help for menstrual-cycle mental health symptoms npj Women's Health 2023 - moderate PMDD There are real, proven treatments for PMDD; knowing them helps you ask for the right help. Clinical guide to recognizing and treating PMDD (SSRIs, hormonal options, lifestyle) Pharmaceutical Journal [Getting help in full](https://niyora.com/research/getting-help/) [Take the two-minute check](https://niyora.com/quiz/) ## This is what the app runs on Niyora turns all of this into three steps you can use in the moment. Reflect on what happened, regulate in about a minute, respond with a clearer head. [Take the quiz](https://niyora.com/quiz/) [Get Niyora](https://apps.apple.com/app/niyora-pms-emotions/id6764561688)