St. John’s Wort
St. John’s Wort is a flower with well-studied medicinal effects.
There has been extensive research on St. John’s Wort, especially on its use in promoting a healthy mood. Like other antidepressants, St. John’s Wort has an impact on sexual function by increasing the level of neurotransmitters (like serotonin) in the brain, but at a different site than typical, synthetic antidepressants. Research has shown an overall effect of increased time-to-ejaculation, supporting St. John’s Wort use for rapid ejaculation.
L-citrulline is another compound studied in sexual health and its role as a key precursor of the nitric oxide cycle is well-studied. Nitric oxide is produced in blood vessels throughout the body and is the principal agent in getting and maintaining an erection. Increasing the level of L-citrulline can promote the generation of nitric oxide, especially in men with lower levels of nitric oxide production-a common occurrence with age.
St. John’s wort (SJW) extracts, prepared from the aerial parts of Hypericum perforatum, contain numerous pharmacologically active ingredients, including aphthodianthrones (e.g., hypericin and its derivatives) and phloroglucinols derivatives (e.g., hyperforin).
Hyperforin is a structurally novel agent isolated from Hypericum perforatum commonly known as St.John’s Wort. Hyperforin used for promoting a healthy mood by blocking the reuptake of the neurotransmitters norepinephrine, serotonin, and dopamine.
Hyperforin is photo and oxygen labile compound that is highly unstable and difficult to isolate in pure form. The standardization of Hypericum perforatum is based on presence of both Hyperforin and Hypericin. It is designated in percentile, meaning that if a 100mg dose of St. John’s Wort is extracted at a standardized 5%, we will get 5 mg of hyperforin from that dose. However, relevant and, in some cases, life-threatening interactions have been reported, particularly with drugs which are substrate of cytochrome P450 and/or P-glycoprotein.
Adverse effects of St. John’s Wort
Adverse effects of St. John’s Wort are also well-studied. Side effects, when they occur, are generally mild and include stomach upset, tiredness, headache, dry mouth, dizziness, and skin rash. It can also increase skin sensitivity to light (photosensitivity).
St. John’s Wort is also known to interact with the cytochrome p-450 (CYP450) system, the body’s primary site of drug break-down. By increasing the activity of the CYP450, St. John’s Wort can result in increased breakdown of other drugs, decreasing their effectiveness. This means the herb can result in significant interactions; some of the specific medications St. John’s Wort interacts with include:
Cyclosporine (Restasis, Neoral)
Verapamil (Verelan, Calan)
Chlozoxazone (Parafon Forte DSC, Lorzone)
Obstructive Lung Disease Drugs
Theophylline (Elixophyllin, Uniphyl)
Gliclazide (Diamicron, Dacadis, Nazdol, Zicron)
Drugs Acting on the Gastrointestinal Tract
Omeprazole (Prilosec, Zegerid)