Common nameKlamath weed
Botanical name
Hypericum perforatumParts used and where grownSt. John’s wort is found in Europe and the United States. It is especially abundant in northern California and southern Oregon. The above-ground (aerial) parts of the plant are gathered during the flowering season.
St. John’s wort has been used in connection with the following conditions (refer to the individual health concern for complete information):
Science Ratings - Health Concerns** - Depression
** - Eczema (topical application)
** - Seasonal affective disorder
** - Somatoform disorders* - Anxiety
* - Cold sores
* - Ear infections (recurrent)
* - HIV support
* - Infection
* - Menopause
* - Ulcerative colitis
* - Wound healing
*** - Reliable and relatively consistent scientific data showing a substantial health benefit.
** - Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
* - For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.
Historical or traditional use (may or may not be supported by scientific studies)
In ancient Greece, St. John’s wort was used to treat many ailments, including sciatica and poisonous reptile bites. In Europe, St. John’s wort was used by herbalists for the topical treatment of wounds and burns. It is also a folk remedy for kidney and lung ailments as well as for depression.
Active constituentsThe major constituents in St. John’s wort include hypericin and other dianthrones, flavonoids, xanthones, and hyperforin.1 While it was previously thought the antidepressant actions of St. John’s wort were due to hypericin and the inhibition of the enzyme monoamine oxidase,2 current research has challenged this belief, focusing on other constituents, such as hyperforin, and flavonoids.3 4 5 Test tube studies suggest that St. John’s wort extracts may exert their antidepressant actions by inhibiting the reuptake of the neurotransmitters serotonin, norepinephrine, and dopamine.6 This action is possibly due to the constituent hyperforin.7 St. John’s wort is able to act as an antidepressant, by making more of these neurotransmitters available to the brain.
How much is usually taken?The standard recommendation for mild to moderate depression is 500–1,050 mg of St. John’s wort extract per day.8 9 10 Results may be noted as early as two weeks. Length of use should be discussed with a healthcare professional. For more severe depression, higher intakes may be used, under the supervision of a healthcare professional.
Are there any side effects or interactions?St. John’s wort has a low incidence of side effects compared to prescription antidepressants. An adverse events profile of St. John’s wort found that, of 14 controlled clinical trials, seven reported no adverse reactions, two had no information, and five reported a total of seven mild reactions.11 Adverse effects reported included stomach upset, fatigue, itching, sleep disturbance, and skin rash. The rate of adverse reactions was always similar to that of the placebo. Additionally, in seven trials comparing St. John’s wort with other antidepressants, the adverse reaction rate for St. John’s wort was consistently lower than that of the antidepressant drugs with which it was compared.
In patients taking simvastatin, treatment with St. John's wort increased serum cholesterol levels, apparently because St. John's wort interfered with the effect of the medication.12
St. John’s wort can make the skin more sensitive to sunlight.13 Therefore, fair-skinned people should be alert for any rashes or burns following exposure to the sun. Three cases of severe blistering and burns were reported in people taking St. John’s wort internally or applying it topically and then being exposed to sunlight.14 There is a case report of a woman experiencing neuropathy (nerve injury and pain) in sun-exposed skin areas after taking 500 mg of whole St. John’s wort for four weeks.15 Although St. John’s wort has photosensitizing properties, the severity of this reaction is not typical for people taking the herb.
People with a history of manic-depressive illness (bipolar disorder) or a less severe condition known as hypomania, should avoid use of St. John’s wort as it may trigger a manic episode.16 17 18 19
There is a single case report in which ingestion of St. John's wort appeared to cause high blood pressure in a 56-year-old man. The blood pressure returned to normal when the herb was discontinued.20Drug InteractionsCertain medicines interact with St. John’s wort: Some interactions may increase the need for St. John’s wort (+), other interactions may be negative (-) and indicate St. John’s wort should not be taken without first speaking with your physician or pharmacist, others may require further explanation (?). Refer to the individual drug article for specific details about an interaction.
Note: The following list only includes the generic or class name of a medicine. To find a specific brand name, use the Medicines index.Atazanavir (-)Benzodiazepines (-)Chemotherapy (-)Cyclosporine (-)Digoxin (-)Fexofenadine (-)Fluoxetine (-)Fluvoxamine (-)Fosamprenavir (-)HMG-CoA Reductase Inhibitors (Statins) (-)Indinavir (-)Nefazodone (-)Omeprazole (-)Oral Contraceptives (-)Paroxetine (-)Phenelzine (-)Sertraline (-)Theophylline/Aminophylline (-)Trazodone (-)Tricyclic Antidepressants (-)Venlafaxine (-)Warfarin (-)
Caution: It is likely that there are many drug interactions with St. John's wort that have not yet been identified. St. John's wort stimulates a drug-metabolizing enzyme (cytochrome P450 3A4) that metabolizes at least 50% of the drugs on the market.21 Consequently, St. John's wort could potentially interfere with a large number of medications. Individuals taking any medication should, therefore, consult with a physician before taking St. John's wort.
Source: www.cncahealth.com