What is Macrotys?

Macrotys is the old Eclectic doctors' name for black cohosh. It is the root and rootstock of Actaea racemosa, once called Cimicifuga racemosa. The plant is a tall woodland herb from eastern North America.

Today it is sold almost entirely for menopause, the time when periods stop. People take it for hot flashes and night sweats. Older folk use covered period pain, joint aches and childbirth.

The honest verdict: human evidence is mixed and far from settled. Some trials show mild relief of hot flashes. Others show no gain over a dummy pill.

It also has a rare but real liver safety question, covered below. And long traditional use is not proof that a remedy works, nor proof that it is safe.

How does Macrotys work?

No one has pinned down how black cohosh works. That matters, because the claims get ahead of the facts.

For years it was described as a plant estrogen. Most laboratory work does not support that. Good products do not appear to act on estrogen receptors in cell tests.

In cell studies, parts of the root bind serotonin receptors. Those receptors help set body temperature. Whether this happens in a woman taking a capsule has not been shown.

Animal and cell work also hints at effects on pain signals and bone cells. None of that has been confirmed in people. Treat it as a lead, not a finding.

What forms does Macrotys come in?

Most products on sale are standardised dry extracts in tablet or capsule form.

Common forms: - Standardised extract tablets, often an isopropanolic or ethanolic type - Capsules of plain powdered root - Liquid tincture in alcohol, the old Eclectic form - Dried root for tea, now uncommon - Combination menopause formulas with soy, red clover or St John's wort

Combination products make trouble hard to trace. If you react badly, you cannot tell which herb did it.

Species mix-ups are a known issue in this trade. Products that name the full botanical source and test for identity are the safer bet.

Where it comes from:

Native peoples of eastern North America used the root for women's complaints, joint pain and snakebite. Settlers copied the practice.

Nineteenth-century Eclectic physicians called it macrotys and ranked it highly. Their texts listed it for rheumatism, period pain, after-birth pain and nervous complaints. King's American Dispensatory gave it a long entry.

It was a main ingredient of Lydia Pinkham's Vegetable Compound, sold from 1876. That product made the root a household name in the United States.

German makers revived it in the 1950s as a menopause remedy. Most modern trials used those German extracts.

What does Macrotys help with?

• Hot flashes and night sweats around menopause: This is the main modern use, and the only one with real trial data. The data is mixed. Several German trials of one standardised extract reported modest relief over about 12 weeks. A large one-year US trial found no benefit over a dummy pill. A Cochrane review pooled 16 trials covering 2,027 women. It found no strong evidence that black cohosh helps hot flashes. So it may help some women a little. It may do nothing. You cannot tell in advance which you are.
• Sleep and mood complaints during menopause: Some trials tracked sleep and mood scores alongside hot flashes. A few reported small gains. These were usually secondary results, not the main question of the trial. That makes them weak evidence. If hot flashes wake you at night, better sleep may simply follow fewer flashes. Direct action on mood has not been shown.
• Period pain: Eclectic doctors used macrotys for cramping period pain and described it as a main remedy. Modern trials of black cohosh alone for period pain are very few and small. There is no reliable human evidence either way. Treat this as tradition, not proof.
• Joint and muscle aches (traditional use): Old American practice used the root for rheumatism and muscular aching. This was one of its oldest jobs. No good human trials back it. Animal and cell work hints at effects on pain signals, which is not the same as relief in people. The human evidence here is essentially absent.
• Bringing on labour (traditional use only, and unsafe): Some traditional midwives used black cohosh, often with blue cohosh, to start labour. This is listed here as history, not as an option. Serious harm to newborns has been reported with these herbs, mostly tied to blue cohosh. The combination has been linked to heart and brain injury in babies. Do not use black cohosh in pregnancy for any reason. Labour care belongs with a midwife or doctor.

What are the side effects of Macrotys?

• Stomach upset or nausea
• Headache
• Dizziness
• Rash or itching
• Breast tenderness
• Weight gain
• Spotting or vaginal bleeding
• Slow heartbeat (rare)
• Liver injury (rare, can be serious)

Good to know:

Most side effects are mild. Stomach upset and headache are the ones seen most in trials.

The serious concern is liver injury. Cases of liver inflammation and, rarely, liver failure have been reported after use.

These cases are rare. Experts still argue over how many were truly caused by black cohosh, and how many involved the wrong plant species.

Regulators in the UK, Australia and the EU judged the risk real enough to require a liver warning on the label. Learn the warning signs listed under 'When to see a doctor'.

How much Macrotys should you take?

• Recommended daily: This page does not tell you what to take. It describes what labels usually say. Standardised extract products commonly list 20 to 40 mg once or twice a day. Some list a dried root equivalent of about 40 mg daily. Trials have used a similar range. Taking more does not appear to work better, and it may raise the chance of side effects. If you have any liver problem, take any hormone-sensitive cancer drug, or are pregnant, see the safety section first.
• Best time of day: Timing does not seem to matter much. Blood levels are not the issue here. Twice-daily products are usually split between morning and evening. Some women take the evening dose closer to bedtime for night sweats. There is no trial evidence that one schedule beats another.
• With or without food: Food is the usual advice. Taking it with a meal lowers the chance of nausea or stomach upset. There is no sign that food changes how well it works. Do not take it with alcohol, which adds strain to the liver.
• Time to effect: Nothing happens quickly. In trials, any change showed up over 4 to 12 weeks. Be ready for it to do nothing at all. In the largest and longest study, it worked no better than a dummy pill. Any sharp relief in the first few days is more likely to be expectation than the herb.
• How long to take it: Most trials ran from 12 weeks to six months. Safety beyond one year has not been properly studied. UK and Australian regulators expect a review by a doctor if use goes past six months. Many labels carry that line. If hot flashes have not changed after about 12 weeks, longer use is unlikely to help.