What is Periwinkle?

Periwinkle (Vinca minor) is a low, creeping evergreen plant with glossy leaves and blue-violet flowers. Western herbalists have used the dried leaf and flowering stem as a drying, tightening (astringent) remedy for mouth sores, sore throats, diarrhoea and heavy periods.

It is also sold as a "brain herb". That is because one of its compounds, vincamine, was turned into a prescription medicine in parts of Europe for poor blood flow in the brain. The herb in a tea bag and that refined medicine are not the same thing.

Here is the honest verdict. Periwinkle has a long European record, but almost no human trial evidence as a whole herb, and traditional use tells you what people did, not that it works. It also carries real risks, so it is not a casual home remedy.

Do not confuse it with Madagascar periwinkle (Catharanthus roseus), a different plant used to make cancer drugs and far more poisonous.

How does Periwinkle work?

No one has shown, in people, how periwinkle leaf works as a herb. What follows is a reasonable idea, not proof.

The leaf holds a group of compounds called indole alkaloids. The best known is vincamine. In lab and animal work, vincamine appears to widen blood vessels in the brain and help brain cells use oxygen.

A drug company later built a lab-made copy of vincamine, called vinpocetine. Studies of that drug cannot be read across to a cup of periwinkle tea, because the amount and purity are completely different.

The leaf also holds tannins, the same drying compounds found in strong black tea. Tannins are the likely reason old texts used periwinkle as a gargle and for loose bowels.

What forms does Periwinkle come in?

Periwinkle reaches shoppers in a few different forms. The most common are the dried leaf and stem, sold loose or in tea bags.

You may also find liquid tinctures (the herb soaked in alcohol) and capsules of powdered leaf. Some products are standardised to a stated amount of vincamine.

Separately, shops sell vinpocetine tablets. These are a lab-made drug based on a periwinkle compound, not the herb, and in some countries they are regulated as a medicine.

Creams and washes made from the leaf appear in older European herbals for skin complaints. These are rare today.

Where it comes from:

Periwinkle has grown in European gardens and woodlands for centuries. Medieval writers called it "sorcerer's violet" and wove it into garlands and charms.

Culpeper and other seventeenth-century English herbalists listed it for nosebleeds, mouth ulcers, bleeding gums and heavy menstrual flow. Continental folk medicine used it much the same way.

In the 1950s, chemists isolated vincamine from the leaf, and by the 1970s it was a prescription drug in several European countries for age-related memory problems.

What does Periwinkle help with?

• Memory and blood flow problems in the brain: This is the modern selling point, and it rests on the drug, not the plant. Human studies looked at vinpocetine, a lab-made copy of a periwinkle compound, and even those results were judged too weak and too small to support its use. No trial has tested periwinkle leaf or tea for memory in people. If you are worried about memory changes, see a doctor rather than treating yourself.
• Heavy menstrual bleeding: This is a long-standing European folk use, based on the herb's drying, tightening action. There is no human trial evidence behind it. Heavy bleeding can have causes that need proper treatment, such as fibroids, a thyroid problem or low iron. Get it checked before trying any herb.
• Nosebleeds and small bleeds: Old herbals recommended chewing the leaf or applying it to stop minor bleeding. That record is genuine and goes back centuries. No modern study supports it. This use also sits oddly with reports that periwinkle compounds may thin the blood, which is one more reason to be careful.
• Mouth ulcers, bleeding gums and sore throat: Periwinkle was used as a gargle or mouth rinse across Western herbalism. The tannins in the leaf do dry and tighten tissue, which fits the traditional picture. No human trial has tested it. Do not swallow a strong rinse, as the alkaloids carry risks that a simple salt-water gargle does not.
• Diarrhoea: Tannin-rich plants have a long record for loose bowels, and periwinkle is one of them. The effect, if any, would be mild and short-lived. There is no trial evidence. Diarrhoea that lasts more than a couple of days, or comes with blood or fever, needs medical care, not a herb.
• High blood pressure (traditional use only): Some European folk sources used periwinkle for high blood pressure. Animal work suggests its alkaloids can widen blood vessels, which would lower pressure. This is not proven in people, and it is not a safe way to manage blood pressure. It also creates a real risk of your pressure dropping too low if you already take blood pressure tablets.

What are the side effects of Periwinkle?

• Nausea and stomach upset
• Loss of appetite
• Dizziness or light-headedness
• A drop in blood pressure
• Flushing (sudden warmth and redness of the skin)
• Headache
• Sleep problems
• Faster or irregular heartbeat
• Easier bruising or bleeding
• Low white blood cell counts, reported with the refined vincamine medicine

Good to know:

Mild stomach upset and dizziness are the effects people report most often. They usually settle when you stop.

The serious concerns come from the alkaloids. These include blood pressure dropping too far, changes in heart rhythm, slower blood clotting and, with the refined drug form, drops in the white blood cells that fight infection.

Large amounts of the raw herb are genuinely toxic. Stop at once and get medical advice if you feel faint, notice a racing or skipping heartbeat, bruise easily, or come down with a fever or sore throat that will not shift.

How much Periwinkle should you take?

• Recommended daily: There is no established safe dose for periwinkle leaf. That is the honest answer, and it is the main reason we do not recommend self-dosing. The alkaloid strength of the raw herb varies a lot between batches, so the same spoonful can be much stronger one time than the next. Older herbals mention small amounts of dried leaf as a tea or a mouth rinse. We are not repeating those figures as a recommendation, because modern safety information does not back them up. If you are considering periwinkle for a brain or circulation problem, talk to a doctor or a qualified herbalist first.
• Best time of day: No best time has been established, because no useful dosing studies exist. Traditional gargles and rinses were used as needed through the day.
• With or without food: No evidence points either way. Taking it with food may reduce stomach upset, which is one of the more common complaints.
• Time to effect: Unknown for the herb. A tannin-based effect on a sore mouth or loose bowels would be felt within hours, while any claimed effect on memory or circulation has never been measured in people.
• How long to take it: Do not take periwinkle long-term without medical supervision. Reports linked to its refined compounds include effects on blood cell counts, which only show up over time. If you use it at all, keep it short and stop if anything feels wrong. Reassess with a health professional after a week or two rather than drifting into months of use.