Evidence: Reasonable Possible Benefits: Reasonable Safety: Low
TABLE OF CONTENTS
What is St. John’s Wort?
Hypericum perforatum, commonly known as St. John’s Wort, is a herbal anti-depressant with a long history of use as a traditional medicine. This herb is often used as a supplement for its anti-depressant effects. While it can be effective in this regard, it can also have a variety of side effects and usually isn’t worth taking unless you have a great reason to do so. This article is about the main benefits of St. Johns Wort, its potential side effects, the best time to take it, and more.
Possible benefits
All of the potential benefits mentioned below are dose-dependent. As with other adaptogenic herbs, there is a sweet-spot dose that allows you to get most of the benefits without causing meaningful side effects or tolerance buildup in the body. We will discuss the best dosing protocol later in this article.
Major benefits
Anti-depressive effects – St. John’s wort inhibits the uptake of serotonin, dopamine, GABA, glutamate, and norepinephrine. This inhibition can have a profound effect on mood and well-being in the short term. St. John’s wort seems most effective for offsetting mild-moderate depression. The herb can be just as effective in this regard as many prescription anti-depressants but generally with much fewer side effects.
Minor benefits
Reduced anxiety – This effect applies to some forms of chronic anxiety but not others. For example, the herb doesn’t seem to improve social anxiety in any way but it may slightly improve generalized anxiety disorder (GAD).
Reduced symptoms of premenstrual syndrome (PMS) – This herb can be somewhat effective in this regard but please keep in mind that there are much safer tools that can also reduce the symptoms of PMS more reliably and effectively.
Reduced symptoms of menopause – This herb can reduce hot flashes and other symptoms related to menopause. Again, keep in mind that there are much safer ways to reduce the symptoms of menopause.
Possible side effects
The side effects below are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.
Allergic reaction – Some people are allergic to this herb and may experience an allergic reaction after they start taking it. Unlike the “initial adverse reaction,” allergic reactions typically don’t go away until one stops taking the herb.
Nausea – This side effect is most common when people take the herb on an empty stomach.
Diarrhea – You can usually prevent diarrhea or stomach discomfort by taking this herb with a meal.
Dizziness
Tingling
Restlessness
Sexual or erectile dysfunction
Addiction – Just like other anti-depressants, St. John’s wort can cause both psychological and physical addiction.
Withdrawal – People often experience withdrawal symptoms when they stop taking the herb. The symptoms are similar to when people stop taking other anti-depressants. They include dizziness, chills, nausea, and fatigue and usually last for about a week. In cases of long-term supplementation, the withdrawal can last for multiple weeks.
Severe skin reactions after sun exposure – This side effect only seems to occur at high doses.
Psychosis in Schizophrenics – St. John’s wort might bring on psychosis in some people with schizophrenia.
Serotonin syndrome – This potentially life-threatening effect can occur either at very high doses or when people combine St. John’s Wort with a variety of drugs or nutritional supplements that impact the same pathways that this herb does.
Worsened Alzheimer’s disease – St. John’s wort might make dementia worse in people with Alzheimer’s disease.
Toxicity – As an adaptogen, St. John’s Wort acts as a mild stressor on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, stressing the body too much can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking very high amounts of this herb could lead to chronic toxicity and cause health problems over time. To prevent chronic toxicity or the buildup of tolerance, staying below 900 mg of an extract standardized for 0.3% hypericin a day is best unless you have a great reason to take more.
Contamination – If growing or storing conditions are not adequately controlled, St. John’s wort can be contaminated with bacteria, molds, and other potentially harmful microorganisms. Some growers also use pesticides and herbicides that can be unsafe. Another issue is that herbal supplements can get contaminated with other supplements and chemicals during the manufacturing process. Choose the brand you get herbs and herbal supplements from wisely. It is often best to use websites like Amazon, where thousands of users have reviewed and rated the products. You are less likely to buy something of lower quality there.
Who should not take St. John’s wort?
You should probably avoid taking St. John’s wort if you:
take anti-depressants or a variety of other medications and supplements that could interact negatively with this herb (see the list below)
are allergic to this herb
suffer from Schizophrenia
suffer from Alzheimer’s disease
have bipolar disorder (the herb may bring on mania or increase the speed of cycling)
have ADHD
experience a severe adverse reaction after taking the herb (though a mild adverse reaction is usually a great thing as it is a sign that the supplement is working and causing a hormetic response that allows the body to adapt and become more resilient)
are pregnant or breastfeeding (St. John’s wort can cause birth defects when taken by pregnant women. When this herb is taken by breastfeeding women, it can cause drowsiness and fussiness in infants)
Who will benefit the most?
You should consider taking the supplement if you:
suffer from depression and have a great reason to take anti-depressants, such as this herb
How much St. John’s wort should you take?
The best dose for the vast majority of people is 0 mg/d. The benefits rarely outweigh the negatives. Only consider taking this herb if you suffer from depression and are not willing to experiment with other, generally safer tools that might help.
The regular dose for an extract standardized for precisely 0.3% hypericin is 300 mg 2-3 times a day. Please keep in mind that even this dose can be problematic for many people. Always start with the lowest end of this dosing range.
Best time to take St. John’s wort
This herb is better taken with food to lower some of the potential side effects.
If you take this herb on an empty stomach, the short-term effects will kick in faster and they will be more pronounced but will not last as long.
Whether you take this herb in the morning or the evening typically does not make much difference. Both options are fine so feel free to experiment.
Interactions
5-HTP 5-HTP increases serotonin levels in the brain and St. John’s wort inhibits the reuptake of serotonin. This combination can lead to serotonin syndrome.
L-tryptophan Although much safer than the combination of St. John’s wort and 5-HTP, this combination is also discouraged.
SSRIs SSRIs and St. John’s Wort cause additive effects on serotonin reuptake inhibition which could lead to serotonin syndrome.
Substances that increase serotonin levels Amphetamines, phenethylamines, and any other substances raising serotonin levels or blocking their reuptake should be avoided when one is taking St. John’s wort.
Warfarin The herb should not be used with Warfarin and other anticoagulants as it can decrease the effects of these substances.
Antipsychotics
Analgesics
Anaesthetics
Anxiolytics
Antiepileptics
Hypertensive medications
Where to buy St. John’s wort?
Only consider buying this herb if you have a very good reason for doing so. While St. John’s wort can be helpful in some scenarios, the negative effects outweigh the positive ones for most people.
Amazon is the best option for ordering St. John’s wort and other herbs and herbal supplements in most countries. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the internet.
Some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.
FAQ
As with most other herbs and herbal supplements, it is best to cycle St. John’s wort and stay off of it for about 4 weeks every 2 months to reset your tolerance back to baseline. This will keep your body sensitive to the herb and allow you to keep getting the benefits in the long term while lowering the effects.
When you take an extract standardized for hypericin, you know exactly how potent it is and how much you need to take to get the desired outcome. Herbal extracts also tend to be cheaper than unextracted powders in many cases. However, many of the potentially beneficial compounds get lost during the extraction process. Therefore, if you know how potent the unextracted powder is, it is almost always a better option.
All of these options are fine. The two most important things to consider are the price and dosing. Powders are almost always the cheapest form. However, you may need a highly accurate scale to dose them correctly (preferably 0.001g). You can get one for as little as $20 from Amazon. Dosing the powders also takes some time that can add up over months or years. The disadvantage of capsules is that they are often made of bovine gelatine, which rarely comes from ethical sources.
Yes, you can. This herb should not impact your sleep in any negative way. Whether you take it in the morning or the evening typically doesn’t make much of a difference. Both options are fine so feel free to experiment.
This herb should not become harmful once it exceeds the expiration date but it can lose potency over time. Keep the herb or the herbal supplement in a cold, dark, and dry place, and it should remain just as potent for many months or even years.
Yes. St. John’s wort is one of the least safe herbs and supplements in general on the market. Even regular doses can cause multiple problems in some people or when the drug is mixed with other substances.
There is usually no point in taking more than 900 mg of an extract standardized for 0.3% hypericin of a dry herb powder daily. This amount should give you most of the benefits with a reasonably low level of harm.
The half-life of St. John’s wort in the body is 26-48 hours. This herb should be processed in your body within a week of consuming it.
Just like for other anti-depressants, the effects of this herb are cumulative. Therefore, you must take it for at least 2-4 weeks to notice most of the benefits. But again, cycling the herb and not taking it at least twice a week is necessary to prevent tolerance in the long term.
Yes, St. John’s wort is vegan-friendly. If you buy this herb in a capsulated form, beware that the capsules often contain animal-based gelatin. Instead, find a brand that puts its products into cellulose capsules.
No, it doesn’t. The herb does not interfere with fasting in any significant way.
References
Most of the information in this guide is based on scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything you read in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.
