Vinpocetine inhibits an enzyme called phosphodiesterase type 1 (PDE1) while reducing intracellular calcium levels, both of which normally cause blood vessels to contract and narrow the diameter of the vessels. This inhibition  allows brain blood vessels to open and increases the amount of blood flowing through them. 

By inhibiting PDE1, as well as through its antioxidant properties, vinpocetine reduces the stickiness of red blood cells and platelets.  This allows blood to flow more easily through narrowed vessels.  Vinpocetine is also a sodium channel blocker that may protect the cells by preventing the accumulation of sodium in injured brain cells.  This may also contribute to preserving brain cells’ ability to restructure themselves after an injury and to rapidly restore cognitive function.  Growing evidence suggests that it may be beneficial in treating or preventing acute ischemic strokes and various forms of dementia.

In chronic vascular ischemia, it is important to increase blood flow to the affected areas to increase the delivery of both oxygen and glucose, the brain’s only source of energy.  Using positron emission tomography (PET) scanning, Hungarian investigators demonstrated that administering vinpocetine led to an increase in glucose transport into the whole brain.  Other researchers showed that vinpocetine increased brain glucose uptake and metabolism, especially in areas nearest  damaged tissue. Other studies using transcranial Doppler ultrasound and other techniques have also demonstrated increased regional blood flow and enhanced glucose supply to brain tissue in response to vinpocetine.  

Data seems to support a role for vinpocetine in acute treatment of stroke, and might be the basis for recommending its regular use in patients at high risk for acute stroke. 

An early analysis of seven small trials reported that patients with various forms of dementia who supplemented with vinpocetine became “more vivid” and saw improvements in their cognitive performance and daily activity.  Because this was a report of multiple trials in differing categories of patients and with different outcome measures, it is difficult to draw any firm conclusions from it. A more recent and rigorous analysis of multiple trials of vinpocetine for cognitive impairment and dementia showed benefit associated with taking oral vinpocetine at doses of 30-60 mg per day.  The number of patients treated for longer than six months was small, however, and because of variability in design and outcome measures in the three studies these authors reviewed, they concluded that there was inconclusive evidence for the use of vinpocetine in patients with dementia. These authors emphasized the need for larger clinical trials with clearly defined inclusion criteria and outcome measurements.

Promising evidence from the laboratory suggests that vinpocetine protects brain tissue from the oxidative stress caused by the “Alzheimer’s protein” known as amyloid beta or Abeta.  Because vinpocetine also blocks the NMDA receptors that are thought to be involved in the genesis of Alzheimer’s disease, vinpocetine supplements have a potential role in preventing Alzheimer’s.

Vinpocetine has long been used in Eastern Europe to treat various forms of hearing disorders. A 1986 review of eight independent studies of substances that enhance blood flow found that vinpocetine produced improvements in hearing as well as in “ringing” of the ears, or tinnitus, following trauma to the ear.  A decade later, an open-label study of vinpocetine at a dose of 20 mg a day for 10 days following trauma to the ear showed that vinpocetine supported significant improvement in hearing and a decrease in tinnitus, with the best results seen in patients who took the supplement within one week of the injury.