Educational information, not medical advice — ask your doctor or midwife.
Ambrosia hispida is a low, creeping coastal plant with grey-green, deeply cut leaves. It grows on sand and rocky shores in Florida, the Bahamas, the Caribbean and parts of Central America. Local names include bay geranium, coastal ragweed and wormwood.
It is a true ragweed, in the same plant family as daisies and marigolds. In the islands and along the coast, people have long boiled the leaves into a bitter tea. The same tea was also used as a wash for sore skin.
Tea from the leaf is the main use. It was taken for colds, cramps, fever and upset stomach, and rubbed on bites and rashes.
Here is the honest verdict. No human trials support any of these uses. Long use in a tradition is not proof that a plant works, and it is not proof that it is safe.
No one has shown how this plant acts in the human body. There is no human research on it at all.
What exists is laboratory work, mostly on related Ambrosia species. These plants are rich in bitter compounds called sesquiterpene lactones.
In test tubes, some of these compounds slow bacteria and single-celled parasites. In cell studies, several of them also kill cells outright, including cancer cells in a dish. Killing cells in a dish is not a treatment, and it is also how a poison behaves.
In cell and animal studies, some Ambrosia extracts appear to damp down signals that drive swelling and pain. Whether a cup of leaf tea does anything similar in a person is unknown.
One thing is well established. The same family of compounds causes the itchy skin rash that ragweed plants are known for. That part is not a theory.
The usual form is a simple tea made from dried or fresh leaf. It is bitter, and it is often sweetened.
Forms you may come across:
- Loose dried leaf and stem, sold in local markets and bush-medicine stalls. - Fresh leaf, crushed and used as a wash or poultice on skin.
- Bundles of the whole plant, dried for later use. - Rarely, a tincture (an alcohol extract) made at home.
It is not a mainstream supplement. You will not often find capsules, standardised extracts or tested products from large makers.
That matters for safety. With no label and no testing, you cannot know the strength of what you have.
The plant has a long record in coastal folk medicine of the Caribbean, the Bahamas and Central America. Written notes on this use go back to the nineteenth century.
Healers brewed the leaf as a "cooling" or cleansing tea. It was given for colds, chest congestion, fever and stomach upset. It was also taken for painful or late periods, and used on the skin for bites, sores and rashes.
Some accounts from the region also list it for worms, which is where the name wormwood comes from locally.
These are historical records of what people did. They are not records of what the plant was shown to do.
Stop using it and get urgent help if you have trouble breathing, wheezing, or swelling of the lips, tongue or face. These can be signs of a severe allergic reaction.
See a doctor the same day if you develop a spreading rash, blisters, or a rash that does not settle after you stop.
See a doctor if you have yellow skin or eyes, dark urine, or pain under the right ribs. These can point to a liver problem.
Also see a doctor if a fever lasts more than three days, if a cough lasts more than three weeks, or if period pain is severe enough to stop your normal day.
Ambrosia hispida is not approved as a medicine in the United States, the United Kingdom, the European Union, Canada or Australia. It is sold in some Caribbean and Central American markets as a local bush herb, with no testing or dose label. Some countries also treat ragweed species as weeds to be controlled, which can limit growing or moving the plant.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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