Custom Periwinkle Tea 
periwinkle is used for “brain health” (increasing blood circulation in the brain, supporting brain metabolism, increasing mental productivity, preventing memory and concentration problems and feebleness, improving memory and thinking ability, and preventing early aging of brain cells).
Periwinkle is also used for treating diarrhea, vaginal discharge, throat ailments, tonsillitis, chest pain, high blood pressure, sore throat, intestinal pain and swelling (inflammation), toothache, and water retention (edema). It is also used for promoting wound healing, improving the way the immune system defends the body, and for “blood-purification.”
A chemical in periwinkle called vincamine can be converted in the laboratory to the compound vinpocetine, which is marketed as a dietary supplement.
Uses & Effectiveness
Preventing brain disorders.
Tonsillitis.
Sore throat.
Intestinal swelling (inflammation).
Toothache.
Chest pain.
Wounds.
High blood pressure.
Other conditions.
More evidence is needed to rate the effectiveness of periwinkle for these uses.
Periwinkle can lower blood pressure. It can also help reduce swelling (inflammation) and have a drying (astringent) effect on the tissues.OverviewUsesSide EffectsPrecautionsInteractionsDosing