What are the best cortisol-lowering supplements for women in the UK?

Four baselines under one curve: the cycle, the pill, the perimenopause and pregnancy, and why the cortisol trials a woman is sold on did not separate any of them

What are the best cortisol-lowering supplements for women in the UK is a question that the shelf answers with the same products it sells men, in pink, and the honest answer starts with the fact that a woman's cortisol curve sits on one of four baselines that the trials behind those products never separated. The curve itself is the same shape in everyone, a rise of about half in the thirty to forty-five minutes after waking, a fall through the afternoon, an evening low, and a brief spike after hard training; what differs in a woman is the baseline it sits on, and there are four. The first is the menstrual cycle: the cortisol response to a stressor differs between the follicular and luteal phases in the laboratory studies, so that a single reading or a single stressful week is read differently depending on where in the cycle it fell, and a woman tracking how stressed she feels is tracking two rhythms at once. The second is the combined oral contraceptive pill, which raises the liver's production of cortisol-binding globulin, the protein that carries most cortisol in the blood, so that a woman on the pill has a higher total cortisol on a blood test while her free, active cortisol is not raised; a woman who has read that her cortisol is high on a test taken on the pill has often read the binding protein, and a doctor interpreting the result knows to ask. The third is the perimenopause, the years around the final period, where disturbed sleep, night sweats and hot flushes raise the evening tail of the curve and produce exactly the wired-at-night, tired-in-the-morning pattern that is sold to as a cortisol problem and is a hormone transition with its own treatments, decided with a doctor. The fourth is pregnancy, where cortisol rises progressively as a matter of normal physiology, where nothing should be taken to lower it, and where the one herb on the shelf with cortisol trials is avoided outright.

Against those four baselines, the trials a woman is sold on are thin in a specific way. Women have been under-represented in supplement and early-phase trials generally, and the ashwagandha cortisol trials, which are the only ones with repeated measured reductions, were mixed-sex or male-weighted, did not report results by cycle phase, did not record contraceptive use, excluded pregnancy and did not study the perimenopause; the single morning serum sample most of them drew is the sample the pill distorts and the cycle shifts. A woman reading a reduction of a fifth to a quarter in those trials is reading a result that may or may not apply to her baseline, and no trial has told her which.

The candidates read against the baseline, the three cautions that matter more to women, the two mimics a blood test finds first, the worked example, and the verdict

Read against the baseline, the candidates sort as follows. Ashwagandha root extract has the measured effect, small randomised trials in stressed adults with cortisol a fifth to a quarter lower than placebo over a couple of months, and three cautions that weigh more heavily in a woman than the general scorecard shows. The liver injury case record is shared with everyone. The thyroid caution is not: a small randomised trial in adults with subclinical hypothyroidism found thyroid hormone levels raised on a root extract, and case reports describe thyrotoxicosis after taking it, and because thyroid disease is several times commoner in women than in men, a woman with a thyroid condition, on thyroid medication, or with the fatigue and weight change that might be an undiagnosed one has a doctor's question before any capsule. The pregnancy exclusion is absolute, and it extends to anyone who might become pregnant while taking it. Phosphatidylserine at 600 to 800mg blunts the post-exercise cortisol spike in small trials, which is the spike a woman who lifts should want intact. The mushroom shelf has never measured the hormone. Magnesium is taken for the claims it has, normal psychological function, normal nervous system function and the reduction of tiredness and fatigue, with the honest note that women's intakes also fall below the reference in the survey, though less often than young men's, and that it has no cortisol claim because none exists. Before any of them, two conditions that mimic a cortisol problem in women are found by a blood test and not by a shelf: an underactive thyroid, which presents with fatigue, slowed thinking, weight gain and cold intolerance and is diagnosed by a thyroid function test, and low iron stores, common in women of reproductive age and presenting with fatigue and poor concentration, measured by ferritin. A woman who feels the way the cortisol shelf describes and has not had those two tests has not yet asked the right question, and a doctor asks it in one appointment.

The worked example is a mineral taken for the claims it has, on any baseline: {FL}, 1500mg magnesium bisglycinate stated as 300mg elemental at 80% NRV, two capsules with the evening meal, carrying the authorised claims for normal psychological function, normal nervous system function, normal muscle function and the reduction of tiredness and fatigue and no claim about cortisol, stress or any hormone because none exists, batch tested for lead, mercury, arsenic and cadmium with the certificate on request, UK made under GMP and BRC, 180 capsules for £19.99 at 22p a day, with the usual note that it is taken in pregnancy only with a doctor's agreement. The verdict on the best cortisol-lowering supplements for women in the UK is that the curve is drawn on a woman's baseline before any product is chosen: the cycle phase, the pill that raises the total without raising the free hormone, the perimenopause that raises the evening tail as a transition rather than a disorder, and the pregnancy in which nothing is lowered; that the one herb with trials carries a thyroid caution that matters more to women and an exclusion in pregnancy; and that the two mimics a blood test finds, thyroid and iron, are checked by a doctor before a woman buys a capsule for a hormone nobody has measured in her.

What to check on the label

Questions people also ask

What is the best supplement to lower cortisol for women?

None until the baseline is drawn, because a woman's cortisol curve sits on one of four baselines the trials never separated: the cycle phase, the combined pill, which raises total cortisol by raising its binding protein without raising the free hormone, the perimenopause, whose disturbed sleep raises the evening tail as a hormone transition rather than a cortisol disorder, and pregnancy, in which nothing is lowered; the one herb with measured reductions, ashwagandha, carries a liver record, a thyroid caution that matters more to women and an exclusion in pregnancy, and the two mimics, an underactive thyroid and low iron, are found by a blood test a doctor orders first.

Does the pill affect cortisol levels?

Yes, on a blood test: the combined oral contraceptive raises the liver's production of cortisol-binding globulin, the protein that carries most cortisol in the blood, so total cortisol reads higher in a woman on the pill while her free, active cortisol is not raised; a woman who has read that her cortisol is high on a test taken on the pill has often read the binding protein, and a doctor interpreting the result knows to ask about contraception, which most of the supplement trials that measured cortisol did not record.

Is ashwagandha safe for women?

It carries three cautions that weigh more heavily in women than the general scorecard shows: the liver injury case record shared with everyone; a thyroid caution, since a small randomised trial in subclinical hypothyroidism found thyroid hormone levels raised on a root extract and case reports describe thyrotoxicosis, and thyroid disease is several times commoner in women, so anyone with a thyroid condition, on thyroid medication or with unexplained fatigue and weight change has a doctor's question first; and an absolute exclusion in pregnancy, extending to anyone who might become pregnant while taking it.

Could my high cortisol symptoms actually be something else?

In women, two conditions mimic the fatigue, poor concentration and wired-but-tired pattern the cortisol shelf describes and are found by a blood test rather than a shelf: an underactive thyroid, commoner in women, presenting with fatigue, slowed thinking, weight gain and cold intolerance and diagnosed by a thyroid function test; and low iron stores, common in women of reproductive age with periods, presenting with fatigue and poor concentration and measured by ferritin; the perimenopause is a third, where disturbed sleep and hot flushes raise the evening tail and the treatments are a doctor's conversation.

Does magnesium lower cortisol in women?

No claim exists and the trials do not support one; magnesium's authorised claims are for normal psychological function, normal nervous system function, normal muscle function and the reduction of tiredness and fatigue, and women's intakes fall below the reference in the national diet survey less often than young men's but often enough that a woman whose plate is short of greens, nuts, seeds and whole grains takes it for those claims at a stated elemental dose, on any baseline, with the usual note that in pregnancy any supplement is taken only with a doctor's agreement.

Sources

1. The sex differences in pharmacology literature: women have been under-represented in early-phase and supplement trials, sex differences in body composition, enzyme expression and hormones can change a compound's effect, and claims that a product does something specific for men or for women require trials powered to detect that difference, which almost no supplement has. PubMed record
2. The ashwagandha and thyroid literature: a small randomised trial in adults with subclinical hypothyroidism reported raised thyroid hormone levels on a root extract, and case reports describe thyrotoxicosis, so that the herb is a question for a doctor in anyone with a thyroid condition or on thyroid medication, and is avoided in pregnancy. PubMed record
3. The cortisol rhythm literature: cortisol peaks in the first hour after waking, declines through the day to an evening trough, rises transiently after intense exercise, and is shifted upward by sleep restriction, late caffeine and prolonged energy deficit, with single samples uninterpretable without the time of day. PubMed record
4. The hypothyroidism literature: an underactive thyroid presents with fatigue, slowed thinking, weight gain and cold intolerance, is common in women, and is diagnosed by a thyroid function blood test and treated with replacement, with symptoms resolving over months. PubMed record

Related answers

• What are the best supplements for women over 40 for hormones in the UK?
• What are the best muscle recovery supplements for women in the UK?
• What are the best supplements for reducing cortisol levels?
• What are the best third party tested supplements?
• Are Amazon supplements 3rd party tested?
• Are NOW supplements on Amazon legit?