Black Seed Oil and Menopause: What the Two Human Trials Actually Measured
Black seed oil and menopause is a phrase currently doing a great deal of commercial work — "fix your hormones", "a natural ally for hormone balance", "the hidden menopause benefit". Behind all of it sit two small human trials. One tested a seed extract in capsules and measured two hormone markers. The other tested oil applied to the skin and found no significant difference in menopause-specific quality of life. Between them, no trial has ever measured a hot flush, a night sweat, sleep quality or mood. That absence is the most useful thing anyone can tell you about this topic, so this article starts there rather than ending there.
For our own oil, see our cold-pressed Ethiopian black seed oil.
The Short Answer
- Two randomised human trials exist in menopausal women. Neither used a menopausal symptom as its primary outcome.
- Sukatendel K and colleagues, Narra Journal 2025;5(1):e1399 (PMID 40352190): 50 postmenopausal women in Medan, Indonesia, single-blinded, eight weeks, a 455 mg Nigella sativa seed extract capsule at 910 or 1,365 mg/day. Estradiol and vaginal maturity index rose significantly versus placebo; FSH did not change. Two participants withdrew because of nausea.
- Alizadeh A and colleagues, Phytotherapy Research 2023;37(5):2012–2023 (PMID 36640148): 60 menopausal women in Tabriz, Iran, triple-blind, eight weeks, oil applied topically to the abdomen. Mixed urinary incontinence and incontinence-related quality of life improved; stress incontinence, urge incontinence, sexual function and menopause-specific quality of life showed no significant difference.
- No trial of Nigella sativa has measured hot flushes, night sweats, sleep disturbance, mood or joint aches in menopause.
- "Hormone balance" has no agreed clinical definition. A single estradiol reading moving in a small eight-week trial is not the same as symptoms improving.
- Sidr & Stone publishes a verified 2.67% thymoquinone figure per batch. That is a statement about a bottle, not about menopause. If you are dealing with menopausal symptoms, a GP or menopause specialist is the right first conversation.
What "Hormone Balance" Actually Means
It means nothing specific, and that is precisely why it sells. A clinician managing menopause works with defined things: symptom scores, bone density, cardiovascular risk, endometrial safety, and where relevant, blood levels of specific hormones interpreted in context. "Balance" is not one of those. It cannot be measured, so it cannot be disproved, so it can be printed on anything.
When you see the phrase, the useful questions are: balanced according to which measurement, in whom, over how long, and compared with what? Applied to black seed oil and menopause, the honest answers are: estradiol and vaginal maturity index; fifty postmenopausal Indonesian women; eight weeks; against placebo. That is a real finding. It is a much smaller finding than the phrase implies.
Trial One: A Seed Extract, Fifty Women, Two Markers
The 2025 study by Sukatendel and colleagues is the first human trial of its kind — the authors say so explicitly, noting that before it, the supporting work was in ovariectomised animal models. Fifty eligible postmenopausal women at Haji Adam Malik Hospital in Medan were randomised into three groups: placebo, 910 mg/day, and 1,365 mg/day of a Nigella sativa seed extract, delivered as an Indonesian herbal capsule containing 455 mg of extract each. Estradiol, follicle-stimulating hormone and the vaginal maturity index were measured at baseline and after eight weeks.
Both extract groups showed significant increases in estradiol and in vaginal maturity index compared with placebo. FSH did not change significantly at either dose, and the two doses did not differ from each other. Two women in the intervention arm withdrew because of nausea.
| Sukatendel et al. 2025 (PMID 40352190) | Detail |
|---|---|
| Design | Single-blinded randomised placebo-controlled trial, one hospital, Indonesia |
| Participants | 50 postmenopausal women across three arms |
| Intervention | Nigella sativa seed extract capsules, 910 or 1,365 mg/day |
| Duration | 8 weeks |
| Measured | Estradiol, FSH, vaginal maturity index |
| Result | Estradiol and vaginal maturity index up; FSH unchanged; no difference between doses |
| Not measured | Hot flushes, night sweats, sleep, mood, bone density, quality of life |
| Tolerability | Two withdrawals due to nausea |
Two structural points matter. It was single-blinded, not double-blinded — participants were blinded, but that is a weaker design than the field standard. And it used a concentrated seed extract in capsule form, which is a different product from a cold-pressed culinary oil. Neither point makes the result worthless; both make it non-transferable to a teaspoon from a bottle.
Trial Two: Topical Oil, Sixty Women — and a Null Result Where It Counted
The second trial is more rigorous in design and more sobering in outcome. Alizadeh A, Mohammah-Alizadeh-Charandabi S, Khodaie L and Mirghafourvand M ran a triple-blind randomised controlled trial in 60 menopausal women in Tabriz, Iran, published in Phytotherapy Research in 2023. Participants applied two to three drops of Nigella sativa seed oil — or placebo — to the abdomen twice daily for eight weeks. Primary outcomes were urinary incontinence and quality of life; sexual function was a secondary outcome.
Mixed urinary incontinence scores were significantly lower in the treatment group, and incontinence-related quality of life significantly higher (mean difference 12.63, 95% CI 2.33 to 22.93). But stress incontinence, urge incontinence, sexual function, and menopause-specific quality of life all showed no significant difference between groups. The authors' own conclusion was that further studies are required before a firm conclusion can be drawn.
| Alizadeh et al. 2023 (PMID 36640148) — outcome | Result vs placebo |
|---|---|
| Mixed urinary incontinence | Significantly better (p = 0.04) |
| Incontinence-related quality of life | Significantly better (MD 12.63; 95% CI 2.33–22.93) |
| Stress incontinence | No significant difference |
| Urge incontinence | No significant difference |
| Sexual function | No significant difference |
| Menopause-specific quality of life | No significant difference |
It is worth pausing on the last row. The one trial that actually asked whether black seed oil changed how menopausal women rated their menopause found that it did not. Articles promising a "hidden menopause benefit" rarely mention it.
The Symptoms Nobody Has Studied
Most people searching this topic are not looking for a vaginal maturity index. They are looking for relief from specific, disruptive things. Here is the honest state of the evidence for each, as of this writing.
| Menopausal symptom | Has any Nigella sativa RCT measured it? |
|---|---|
| Hot flushes / vasomotor symptoms | No |
| Night sweats | No |
| Sleep disturbance | No |
| Mood, anxiety or low mood in menopause | No |
| Joint and muscle aches | No |
| Brain fog / concentration | No |
| Bone density or fracture risk | No |
| Menopause-specific quality of life | Yes — one trial, no significant difference |
| Vaginal maturity index | Yes — one small single-blind extract trial, increased |
| Urinary incontinence | Yes — one topical-oil trial, mixed incontinence improved |
Seven of the ten rows most people care about are blank. That is not a criticism of black seed oil; it is a description of a research gap. But a gap in the evidence is not the same as a gap in the marketing, and the difference is where money changes hands.
Post-menopausal cardiovascular risk is a genuinely separate question, and there the literature is deeper — a 2014 randomised trial by Ibrahim RM and colleagues in the Journal of Translational Medicine reported lipid changes in menopausal women taking seed powder. We cover that territory in our article on black seed oil and cholesterol, and the wider cardiovascular picture in our heart health article, rather than repeating them here.
Safety, Medication and Hormone-Sensitive Conditions
"Natural" is not a safety category. Nausea was troublesome enough in the 2025 trial to cause withdrawals, and there are three situations where the caution is more than theoretical.
If you take an anticoagulant, the interaction question is legitimate: Wang Z and colleagues reported in Chemico-Biological Interactions in 2022 that thymoquinone competitively inhibits warfarin 7-hydroxylation via CYP2C9 in laboratory conditions, and modelled that intakes above roughly 1 g per day of N. sativa oil might affect warfarin's pharmacokinetics. That is an in-vitro prediction rather than an observed human interaction — but a pharmacist should hear about it before you start, not after. Additive effects with blood-pressure and blood-glucose medication follow the same logic.
If you have or have had a hormone-sensitive condition, or you take any hormone-related medication, the fact that a trial reported rising estradiol is a reason to ask a clinician first rather than a reason to buy. And if a menopause specialist has recommended a course of treatment, this article is not a case for changing it — we are not positioning a food supplement against anything a doctor has prescribed, and you should not either. See our drug interactions guide and safety guide.
| If you... | Sensible default | Who to ask |
|---|---|---|
| Take any hormone-related medication | Ask before starting anything new | GP or menopause specialist |
| Have or have had a hormone-sensitive condition | Do not self-prescribe supplements | Your specialist |
| Take warfarin or another anticoagulant | Do not start without advice | Pharmacist or anticoagulant clinic |
| Take blood-pressure or diabetes medication | Do not start without advice | GP or pharmacist |
| Experience unexpected bleeding after menopause | Seek medical assessment promptly | GP — this always needs investigating |
| Have surgery scheduled | Declare every supplement you take | Surgical team |
Why a Trial Dose Cannot Be Read Off a Retail Bottle
There is one further practical problem. The 2025 trial used a standardised capsule extract; the 2023 trial used oil on the skin. Neither maps onto a teaspoon of culinary oil, and even if it did, thymoquinone content varies enormously between products. Khaikin E, Chrubasik-Hausmann S, Kaya S and Zimmermann BF measured eleven commercial Nigella sativa products by HPLC-UV for Nutrients in 2022 and found a range of 3.08 to 809.4 mg per 100 g — a more than 260-fold spread.
Certainty about the wider evidence base is also low. An overview of 20 meta-analyses by Li Z and colleagues in Frontiers in Nutrition in 2023 graded 88 of 110 outcome indicators as very low certainty and rated fifteen of the twenty reviews critically low on methodological quality. For a fuller walkthrough of what to look for in a bottle, see our guide to choosing a high-quality black seed oil and our thymoquinone guide.
Why Sidr & Stone
We are not going to sell you a menopause outcome, because the research does not support one and you deserve better than a guess dressed as a promise. The narrow, defensible claim we will make is about the bottle. When we evaluated 36 suppliers before selecting our seed, the thing that separated them was not marketing language — it was whether a per-batch thymoquinone figure existed at all.
- Sidr & Stone's black seed oil is independently verified at 2.67% thymoquinone, tested per batch by Analytice, an ISO-accredited French laboratory, with a Certificate of Analysis you can read for yourself.
- Organically grown Ethiopian highland Nigella sativa, chosen after a 36-supplier evaluation.
- Cold-pressed below 40°C, because thymoquinone is heat-sensitive.
- 100% pure — one ingredient, Nigella sativa seed oil, nothing added.
- Unrefined, which preserves the oil's natural integrity; fine natural sediment is normal.
- Bottled in matte black UV-protective glass, because thymoquinone is light-sensitive.
- Halal certified.
- 10% of profits to charity.
- Fulfilment in the UK, EU, and US.
We will not tell you Sidr & Stone is the strongest or the best — that would be the very claim this article warns against. What we will say is that our thymoquinone figure is 2.67%, independently verified per batch, and the evidence is there to see.
Frequently Asked Questions
Does black seed oil help with menopause?
We cannot say that it does, and we do not claim it. Two small trials measured narrow outcomes — hormone markers in one, urinary symptoms in the other — and the single trial that assessed menopause-specific quality of life found no significant difference. For menopausal symptoms, speak to a GP or menopause specialist.
Can black seed oil increase oestrogen levels?
One small single-blind trial in 50 postmenopausal women reported significantly higher estradiol after eight weeks of a seed extract capsule, with no change in FSH. That is a hormone marker in one population, using an extract rather than a cold-pressed oil, measured once at eight weeks. It is not evidence that symptoms change, and anyone with a hormone-sensitive condition should ask a clinician first.
Has any trial measured hot flushes or night sweats?
No. Searching the published randomised literature for Nigella sativa alongside hot flushes, vasomotor symptoms or the Kupperman index returns no trial that used them as an outcome. Any article implying black seed oil has been shown to reduce hot flushes is going beyond the evidence.
Is black seed oil an alternative to hormone therapy?
It has never been compared with any hormone therapy in a trial, so there is no basis for calling it an alternative to one — and we would not suggest it as a substitute for anything a clinician has recommended. Treatment decisions in menopause belong with your GP or menopause specialist.
Does a higher thymoquinone percentage matter for menopause?
Not in any way the evidence can currently support. A verified percentage tells you how much of the studied compound is in the bottle; it does not tell you that more of it produces a better menopausal outcome, because no trial has tested that. Verification is about knowing what you have bought.
What does black seed oil actually do in the body?
As a food it supplies mostly unsaturated fats — largely linoleic and oleic acid — plus small amounts of thymoquinone, which is fat-soluble, heat-sensitive and light-sensitive. Beyond that, effects in women have been measured only in a handful of narrow markers in small, short trials.
What should I check before buying black seed oil?
Ask for a per-batch Certificate of Analysis from a named independent laboratory, showing a measured thymoquinone figure rather than a range or an "up to" number. With commercial products spanning 3.08 to 809.4 mg per 100 g, an unverified label tells you very little.
Is black seed oil a medicine?
No. Black seed oil is a food supplement, not a medicine. It has a long traditional history and an interesting body of research around thymoquinone, and can be a worthwhile part of a healthy routine — but it does not cure diseases and is not a substitute for medical care. Be cautious of any black seed oil marketed with specific disease-cure claims.
Final Thoughts
Three objections deserve a straight answer. The first: two randomised trials is real evidence, and we are being dismissive. We are not — both are genuine studies and we have described them in detail rather than waving them away. The issue is scope. Fifty women and sixty women, eight weeks each, one country each, measuring markers and urinary symptoms rather than the things that bring people to this search.
The second: menopausal symptoms fluctuate, and plenty of people say black seed oil helped. That is exactly why blinded trials exist. Vasomotor symptoms in particular vary week to week and respond strongly to placebo in controlled studies, which is why an uncontrolled personal improvement — real as it feels — cannot settle the question. It is also why the single-blind design of the 2025 trial is worth noticing rather than glossing over.
The third: it is natural, so where is the harm? Nausea caused two withdrawals in a fifty-person trial, thymoquinone inhibits CYP2C9 in laboratory conditions, and the people reading menopause articles are disproportionately likely to be on medication. "Natural" describes an origin, not a safety profile.
Menopause is a phase of life that deserves proper care — from clinicians who can assess symptoms, risks and options properly. A food supplement is not that, and no honest brand should pretend otherwise. If you want black seed oil in your routine as a food, the one thing we can genuinely offer is a bottle whose contents are measured rather than asserted. Our cold-pressed Ethiopian black seed oil — independently verified at 2.67% thymoquinone — is available now, with fulfilment in the UK, EU, and US.
Shop Sidr & Stone Cold-Pressed Ethiopian Black Seed Oil — Verified 2.67% Thymoquinone →
References
- Sukatendel K, Hasibuan RH, Siregar MF, Faradina D, Edianto D, Lintang LS, Rusda M, Inriani V. Effect of Nigella sativa seed extract on estradiol, FSH levels, and vaginal maturity index in menopausal women: a randomized controlled trial. Narra Journal 2025;5(1):e1399. PMID 40352190. doi:10.52225/narra.v5i1.1399
- Alizadeh A, Mohammah-Alizadeh-Charandabi S, Khodaie L, Mirghafourvand M. Effect of Nigella sativa L. seed oil on urinary incontinence and quality of life in menopausal women: a triple-blind randomized controlled trial. Phytotherapy Research 2023;37(5):2012–2023. PMID 36640148. doi:10.1002/ptr.7725
- Ibrahim RM, Hamdan NS, Mahmud R, Imam MU, Saini SM, Rashid SN, Abd Ghafar SA, Latiff LA, Ismail M. A randomised controlled trial on hypolipidemic effects of Nigella sativa seeds powder in menopausal women. Journal of Translational Medicine 2014;12:82. PMID 24685020. doi:10.1186/1479-5876-12-82
- Li Z, Wang Y, Xu Q, Ma J, Li X, Yan J, Tian Y, Wen Y, Chen T. Nigella sativa and health outcomes: an overview of systematic reviews and meta-analyses. Frontiers in Nutrition 2023;10:1107750. PMID 37057067. doi:10.3389/fnut.2023.1107750
- Wang Z, Wang Z, Wang X, Lv X, Yin H, Jiang L, Xia Y, Li W, Li W, Liu Y. Potential food-drug interaction risk of thymoquinone with warfarin. Chemico-Biological Interactions 2022;365:110070. PMID 35921950. doi:10.1016/j.cbi.2022.110070
- Khaikin E, Chrubasik-Hausmann S, Kaya S, Zimmermann BF. Screening of thymoquinone content in commercial Nigella sativa products to identify a promising and safe study medication. Nutrients 2022;14(17):3501. PMID 36079759. doi:10.3390/nu14173501
Disclaimer: This article describes what published research on black seed oil in menopausal women has and has not measured at the time of writing; research findings and product specifications may change, and readers should check current sources. It is not a recommendation to use black seed oil for menopause, menopausal symptoms or any hormone-related condition, and it is not an alternative to any treatment a clinician has recommended. Black seed oil is a food supplement, not a medicine, and is not a substitute for medical treatment of any condition. Anyone taking prescribed medication, or with a hormone-sensitive condition, should speak to a GP or pharmacist before taking any supplement. For any health concern, consult a qualified medical professional.