Educational information, not medical advice — ask your doctor or midwife.
Lachesis mutus is a homeopathic remedy. It is made from the venom of the bushmaster snake, a large pit viper of South America. The snake is also called surukuku.
Homeopaths give it for hot flushes, night sweats and sore throats. It is also used for symptoms that start on the left side of the body. It is a single remedy, so it is taken on its own.
The venom is diluted over and over, so at 30C not one molecule of it is left. Trials do not show that it beats a dummy pill. Lachesis has a long place in homeopathy, but long use is not proof of effect, and this point is made once here only.
Homeopathy is built on the idea that "like cures like". Raw bushmaster venom causes bleeding, heat and swelling. So homeopaths give the diluted venom to people with flushing, throbbing or bleeding problems.
Each step of the making adds water or alcohol and a hard shake. Homeopaths believe this leaves an imprint of the venom behind. There is no known way in physics or biology for that to happen.
By 12C, and far more so by 30C, no venom is left at all. So the remedy has no known way to act on your body. Any change you feel is most likely a placebo effect (feeling better because you expect to).
The most common form is a small sugar pellet that you let melt under the tongue. Liquid drops in an alcohol base are also sold.
Usual strengths are 6C, 12C, 30C and 200C. Some homeopaths also use LM strengths. The bigger the number, the more the venom has been diluted away.
Pellets are usually made with lactose (milk sugar). Drops usually contain alcohol. Check the label if either matters for you.
Lachesis came into homeopathy in 1828. Constantine Hering, a German-born doctor working in South America, prepared the venom and is said to have tested it on himself.
It soon became one of the best known remedies in homeopathic practice. It is still listed in homeopathic texts and sold worldwide today. Its standing is within homeopathy alone, not in older herbal or folk systems.
See a doctor the same day if you have a sore throat with a high fever, drooling, or trouble breathing or swallowing.
Get urgent help for bleeding that will not stop, blood in your urine or stool, black tarry stools, or bruises that appear for no reason.
Also call a doctor for a sudden very bad headache, chest pain, a racing heartbeat, fainting, a swollen and painful leg, or any bleeding after childbirth. Book a normal appointment if hot flushes, sweats or period problems are wearing you down, so you can talk about treatments with real evidence behind them.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
Reviewed by the HealisticMD editorial team How we grade evidence →
The published evidence for Lachesis mutus is weak or absent. That usually means no controlled trial has tested it, not that a trial found it ineffective — the two are different, and we grade only what has been published.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
One email with the summary. We'll also send a short weekly evidence update — unsubscribe any time.