Educational information, not medical advice — ask your doctor or midwife.
Hierba del negro is a desert mallow plant used in Mexican folk medicine. Its botanical name is Sphaeralcea angustifolia. In English it is called narrowleaf globemallow.
It grows as a grey-green shrub with small orange flowers. The dried leaves, stems and flowers are the parts used. They are brewed into tea or soaked to make a skin wash.
Folk healers reached for it for sore joints, stomach trouble and skin sores. Mexican labs have since studied the plant closely.
Here is the honest verdict. Almost all of that work is in cells and in lab animals. Good human trials are missing, so the effects in people are unproven.
Long use in a tradition is not proof that a plant works. It is not proof that a plant is safe, either. Both still have to be tested.
No one has shown how this plant acts in the human body. The proposed story comes from lab work.
In cell studies, extracts lower the output of chemicals linked to swelling and pain. Two plant compounds, sphaeralcic acid and tomentin, seem to drive much of that effect.
In rodent studies, extracts have eased swollen paws and joint swelling. Animal results often fail to repeat in people.
Like other mallows, the plant holds mucilage. That is a slippery gum that swells in water. It may coat the throat and gut lining, which could explain the old use for sore stomachs.
None of this has been confirmed in human trials. Treat the mechanism as a hopeful idea, not a fact.
Dried aerial parts (the leaves, stems and flowers) are the usual form.
Loose dried herb for tea is the most common. It is sold in Mexican markets and herb shops.
Tinctures also exist. These are alcohol extracts taken in drops.
Some sellers offer capsules of ground herb. These are far less common.
Topical washes and poultices are made from the soaked plant. Tradition used them on the skin, not by mouth.
Research groups have grown the plant in lab cell cultures to get richer extracts. Those are study materials and are not sold to the public.
There is no accepted standard strength. Labels rarely tell you how much active compound is inside.
The plant has a long record in Mexican folk medicine. Healers there used it across dry regions of central and northern Mexico.
It was given as a tea for stomach pain and gut upset. It was also used for sore, swollen joints.
Washes and poultices were applied to wounds, boils and skin rashes. Some records note use for mouth and throat soreness.
From the 1990s onward, Mexican research institutes took an interest. They isolated its compounds and tested them in cells and animals.
That work gave the plant a name in herbal research circles. It did not produce the human trials that would settle the question.
Stop using it and see a doctor if you get a rash, itching or swelling.
Get help the same day for stomach pain that keeps up, black stools or vomiting blood.
Go to an emergency department for swelling of the lips, tongue or throat, or for trouble breathing.
See a doctor if a joint stays hot, red and swollen, or if a skin sore spreads or oozes pus.
In Mexico it is sold freely as a traditional herbal product in markets and herb shops. In the United States, the UK and the EU it is not approved as a medicine. Where it is sold, it is sold as a supplement or herb, and no health claim has been checked by a regulator.
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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