Forskolin: Benefits, Side Effects, Best Time to Take It & More

Forskolin

(Coleus Forskohlii, Plectranthus Barbatus)

Evidence: High
Possible Benefits: High
Safety: High

What is Forskolin?

Forskolin is the main bioactive compound in Coleus forskohlii, an adaptogenic herb with a long history of use as a traditional medicine. Forskolin is often used as a supplement for increasing testosterone and brain function but it may have a wide variety of other beneficial effects. This article is about the main benefits of Forskolin, 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 adaptogens and 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

Reduced asthma – The supplement appears very effective at reducing asthmatic symptoms.
Increased bone mineral density – One study found a significant improvement in men over 12 weeks of supplementation.

Minor benefits

Increased lean mass – In one study, individuals who took the supplement gained 2 lbs more muscle mass than the placebo group. This may partially be confounded with an increase in bone mass, as lean mass is inclusive of bone and skeletal muscle.
Increased HDL – Forskolin seems to increase HDL cholesterol to a remarkable degree but more human research is needed to prove this benefit.
Increased testosterone – Unfortunately, this increase is not very potent and somewhat unreliable.
Reduced fat mass – This effect was observed in obese and overweight individuals. It may not apply to other groups of people.
Reduced fatigue – More research is needed to confirm this effect but a reduction in fatigue and sleepiness was noted in at least one study.
Reduced intraocular pressure – Both eyedrops with Forskolin and oral extracts seem effective for reducing intraocular pressure (IOP).

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.

Increased stomach acid – Forskolin can notably increase stomach acid, which could be a problem for people suffering from stomach ulcers.
Initial adverse reaction – When you start taking Forskolin, things can get worse before they get better. This supplement can temporarily worsen some aspects of your health and even make you sick for a few days after you start taking it. This can be unpleasant but it is usually a sign that the supplement is working and creating a hormetic response that allows the body to adapt and become more resilient in the long term.
Allergic reaction – Some people are allergic to Coleus forskohlii 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 Coleus forskohlii or Forskolin on an empty stomach.
Diarrhea – You can usually prevent diarrhea or stomach discomfort by taking this supplement with a meal.
Toxicity – As an adaptogen, Forskolin 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. The LD50 in cats is about 68 mg/kg. While acute toxicity is extremely rare, taking very high amounts of Coleus forskohlii or Forskolin could lead to chronic toxicity and cause health problems over time. To prevent chronic toxicity or the buildup of tolerance, staying below 50 mg of Forskolin or 5 grams of dry Coleus forskohlii a day is best unless you have a great reason to take more.
Contamination – If growing or storing conditions are not adequately controlled, Coleus forskohlii 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 Forskolin?

You should probably avoid taking Forskolin if you:

have stomach ulcers (Forskolin can notably increase stomach acid, which could be a problem for people suffering from stomach ulcers)
suffer from polycystic kidney disease
are allergic to Coleus forskohlii
experience a severe adverse reaction after taking the supplement (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 (while it can be safe to take this adaptogen during pregnancy or breastfeeding, it acts as a mild stressor and can cause some unnecessary risk to the child)
suffer from an autoimmune disease (adaptogenic herbs, including Coleus forskohlii, can stimulate the immune system, which can worsen symptoms of autoimmune diseases, such as lupus or multiple sclerosis)

Who will benefit the most?

You should consider taking the supplement if you:

have a low bone mineral density
are obese
wish to optimize testosterone
want to gain muscle mass
experience asthma
wish to improve memory and general cognition
have a high budget for supplements and are willing to experiment with a variety of them (Forskolin appears safe and is unlikely to do more harm than good for most people)

How much Forskolin should you take?

Because Forskolin is an adaptogen, it acts as a mild hormetic stressor on the body, which allows your body to adapt and become more resilient to certain kinds of stressors in the long term.

A higher dose does not necessarily lead to more pronounced benefits. Instead, there appears to be an inverted U-shaped dose-response pattern. In other words, you want to find a sweet-spot dose that allows you to get the benefits of Forskolin without putting too much stress on the body or quickly causing the body to develop tolerance to this herbal compound.

The sweet-spot dose typically ranges anywhere between 10-50 mg of Forskolin, which can be found in about 3 grams of dry Coleus forskohlii powder. If you buy an x:1 Coleus forskohlii extract, divide the dry herb dosage by x.

The higher end of this range usually provides slightly more benefits in the short term. If you plan to take this supplement for a longer time (multiple months or years), the lower end is probably a better way to go since you would develop tolerance faster if you were to take higher doses.

While higher doses are generally safe, taking more than the sweet-spot dose daily would be counter-productive as your body would quickly develop tolerance.

Additionally, very high doses can put too much stress on your system and cause health problems if you take the supplement for a prolonged period.

While this supplement could theoretically cause acute toxicity, you would need to take an extremely high dose that is way beyond what is generally found in even the most potent supplements.

Like with most other adaptogens, it is best to cycle Forskolin and take about 2 days off weekly to reset your tolerance. This will allow you to keep getting the benefits in the long term.

Keep in mind that the effects of Coleus forskohlii 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.

Best time to take Forskolin

You can take this supplement with or without food. Each of these options has its benefits. Forskolin, as well as many of the other bioactive compounds in Coleus forskohlii, should absorb well either way.

If you experience nausea or stomach discomfort when you take this supplement, taking it with food should prevent these unpleasant effects or at least make them less intense.

If you take this herbal extract 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 supplement in the morning or the evening typically does not make much difference. Both options are fine so feel free to experiment.

Interactions

Artichoke extract
This combination can increase cAMP levels more than forskolin itself, which can lead to an improvement in attention, information processing, and memory.
Calcium channel blockers
Calcium channel blockers are a type of medicine used to decrease blood pressure. Taking these together with Forskolin may cause your blood pressure to temporarily drop too low.

Where to buy Forskolin?

Amazon is the best option for ordering Forskolin and other 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 herbal supplements, it is best to cycle Forskolin and stay off of it for about 2 days per week to reset your tolerance back to baseline. This will keep your body sensitive to the supplement and allow you to keep getting the benefits in the long term.

When you take an extract standardized for Forskolin, 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 supplement 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 supplement should not become harmful once it exceeds the expiration date but it can lose potency over time. Keep the supplement in a cold, dark, and dry place, and it should remain just as potent for many months or even years.

As an adaptogen, Coleus forskohlii acts as a mild stressor on the body. This is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, putting too much stress on the body can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking very high amounts of Coleus forskohlii or Forskolin could lead to chronic toxicity and cause health problems over time. Very high doses can also make you develop tolerance much faster than lower doses so they may be less effective in the long term.

While you could safely take higher doses, there is usually no point in taking more than 50 mg of Forskolin or 5 grams of dry Coleus forskohlii daily. This amount should give you most of the benefits without meaningful side effects. Paradoxically, taking a higher dose would likely lead to fewer benefits as the body would quickly become accustomed to the supplement.

The half-life of Forskolin in the body is about 74 minutes. This supplement should be processed in your body within 5 hours of consuming it.

The effects of this supplement are cumulative. Therefore, you must take it for at least 2-4 weeks to notice most of the benefits. But again, cycling the supplement and not taking it at least twice a week is necessary to prevent tolerance in the long term.

Yes, Forskolin is derived from a herb called Coleus forskohlii and is therefore vegan-friendly. If you buy this supplement 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 supplement 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.

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