Lesser Periwinkle Extract
Also known as: Lesser Periwinkle Extract, Vinca minor extract, Apovincamine ethyl ester, Vinpocetine
Overview
Vinpocetine is a synthetic ethyl ester derived from apovincamine, an alkaloid found in the leaves of the Lesser Periwinkle plant (*Vinca minor*). It is marketed as a cognitive enhancer and vascular agent, primarily studied for its potential to improve cognitive impairment, dementia, and cerebral blood flow. While related species like *Catharanthus roseus* (Madagascar Periwinkle) are known for their anticancer properties, these effects are distinct from *Vinca minor* and vinpocetine. The research on vinpocetine's efficacy for cognitive benefits is considered moderate, with known basic pharmacological mechanisms but inconclusive clinical evidence, often limited by study quality. Regulatory approval for vinpocetine as a drug is lacking in many countries, and it is often sold as a dietary supplement.
Benefits
Vinpocetine has been investigated for its potential to improve cognitive impairment, particularly in cases of vascular dementia and Alzheimer's disease. However, a Cochrane systematic review found no conclusive evidence to support its clinical efficacy in improving cognition or symptoms of dementia. Some studies have reported mild, inconsistent improvements in memory and concentration in elderly individuals or stroke patients with mild to moderate cognitive symptoms, but these benefits are not robust. There is no proven benefit for severe dementia. The effect sizes observed in randomized controlled trials are generally small or statistically non-significant, with confidence intervals often indicating no effect. It is important to note that the well-established anti-cancer, anti-inflammatory, and antimicrobial activities are associated with *Catharanthus roseus* (Madagascar Periwinkle) extracts, not *Vinca minor* or vinpocetine. The time frame for any potential benefit onset is not clearly established due to varied study durations.
How it works
Vinpocetine primarily functions as a cerebral vasodilator, aiming to increase blood flow and oxygen utilization within the brain. Its mechanism of action involves the inhibition of phosphodiesterase type 1 (PDE1), which leads to increased cyclic GMP levels and subsequent vasodilation. Additionally, vinpocetine modulates voltage-gated sodium channels, which can contribute to neuroprotective effects by reducing neuronal excitability and potentially mitigating ischemic damage. It may also exert antioxidant properties, further contributing to neuroprotection. Vinpocetine is orally bioavailable, meaning it can be absorbed when taken by mouth, but it undergoes first-pass metabolism, which can reduce the amount of the active compound reaching systemic circulation.
Side effects
Vinpocetine is generally considered relatively safe at typical doses, though comprehensive safety data are limited by the small size and short duration of many studies. Common side effects, reported in over 5% of users, include facial flushing, headache, nausea, dizziness, and sleep disturbances. Less common side effects (1-5%) include hypotension (low blood pressure) and general gastrointestinal discomfort. Rare side effects (less than 1%) may include allergic reactions and an increased risk of bleeding, particularly due to its effects on blood flow. Caution is strongly advised when combining vinpocetine with anticoagulants (blood thinners) or antiplatelet drugs, as this combination can significantly increase the risk of bleeding. Vinpocetine is contraindicated during pregnancy and breastfeeding due to insufficient safety data. Its safety in children and healthy young adults has not been established, and therefore, its use in these populations is not recommended.
Dosage
Clinical studies typically utilize vinpocetine doses ranging from 5 to 30 mg per day. The optimal dosage range, based on limited clinical trials, is generally considered to be 10–30 mg per day, taken orally in divided doses. Doses up to 40 mg per day have been used in some studies without serious adverse effects, but the long-term safety at this or any dose is not well-established. Vinpocetine is usually recommended to be taken orally with meals, as this can improve its absorption. It is available in oral tablet or capsule forms, and the purity and standardization of vinpocetine can vary significantly among different dietary supplement products. While orally bioavailable, food intake may influence its absorption, though no specific cofactors are required.
FAQs
Is vinpocetine effective for dementia?
Current high-quality evidence, including systematic reviews, does not conclusively support vinpocetine as an effective treatment for dementia or significant cognitive improvement.
Is it safe to take vinpocetine daily?
Vinpocetine is generally considered safe for short-term use at recommended doses, but long-term safety data are insufficient, and caution is advised.
Can vinpocetine improve memory in healthy adults?
There is no robust scientific evidence to support the claim that vinpocetine enhances cognitive function or memory in healthy individuals without pre-existing impairment.
Does vinpocetine interact with blood thinners?
Yes, caution is warranted. Vinpocetine may increase the risk of bleeding when taken concurrently with anticoagulant or antiplatelet medications.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/12535455/ – This Cochrane systematic review and meta-analysis evaluated vinpocetine for cognitive impairment and dementia. It concluded that there is no conclusive evidence from high-quality studies to support the clinical efficacy of vinpocetine in improving cognition or dementia symptoms, despite some mild side effects being reported. The review highlighted limitations such as small sample sizes and methodological issues in included studies.
- https://www.opss.org/article/vinpocetine-dietary-supplement-products – This regulatory and clinical overview discusses the safety and efficacy of vinpocetine in dietary supplements. It summarizes clinical data suggesting mild cognitive improvements in some elderly and stroke patients with mild cognitive impairment, but notes the lack of large-scale randomized controlled trials. The article also details common side effects like flushing and headache, and warns about potential interactions with blood thinners, while raising concerns about regulatory oversight.
- https://pubmed.ncbi.nlm.nih.gov/38651238/ – This systematic review focuses on the pharmacological and phytochemical aspects of *Catharanthus roseus* (Madagascar Periwinkle). It highlights the anti-cancer, anti-inflammatory, and antimicrobial properties of this species, which are distinct from *Vinca minor* and vinpocetine. The review is primarily based on preclinical studies, indicating a need for more clinical research on *Catharanthus roseus* but is less relevant to the cognitive effects of vinpocetine.
