hibiscus dried flowers

Like all herbal remedies, hibiscus tea (Hibiscus sabdariffa) has a number of often potent effects. However, we should know the right situations to use them as it can interfere with certain medications.

Hibiscus tea may interfere with some medications by having the same properties, affecting their absorption into your body, or speeding up their removal. Medications that hibiscus tea may interfere with include some used to control blood pressure, blood sugar, cholesterol, or inflammation.

Let’s learn more about hibiscus tea to see if it is right for you or if your medications mean you should avoid drinking it.

 Hibiscus Tea Australia

Hibiscus and medications for high blood pressure

As hibiscus tea can lower blood pressure itself, it can also speed up or slow down the clearance of blood pressure medication when they are used together. If you are on medication for high blood pressure, hibiscus tea may not be suitable for you.

Some antioxidants in hibiscus tea can reduce or increase concentrations of blood pressure medication. These effects are through their abilities to speed or slow detoxification or impair absorption of certain drugs.

Hibiscus and medications for high blood pressure

When two drugs or natural remedies are used together but have the same property, including hibiscus tea and blood pressure medications, this can lead to an additive effect. The result is what we can expect if you add the effects of each drug together.

For example, if hibiscus tea would make your blood pressure fall by 10 points, and your medication decreases it by 12 points, you could have a total reduction of 22 points. Therefore, drinking hibiscus tea while taking blood pressure medication may give you a better result or accidentally push your blood pressure too low.

Hibiscus tea can interfere with the functions of Captopril, Losartan, and Simvastatin, all prescribed for cardiovascular issues. Let’s read on to see how hibiscus can affect those drugs if they are used together.

Hibiscus and Captopril

Captopril is a blood pressure medication with roughly equal efficacy to hibiscus when it comes to relieving hypertension. However, when using them together, hibiscus may reduce the amount of Captopril circulating in your bloodstream. This prevents the drug from lowering your blood pressure.

Hibiscus tea can most likely reduce Captopril through its antioxidant content. Not only does hibiscus increase your levels of glutathione, a powerful antioxidant involved in detoxification, but its quercetin content may reduce the absorption of Captopril in the intestine.

In a lab study, hibiscus tea sped up the detoxification of Captopril, and flattened out its peak level in the body. While this has the potential to make Captopril less effective, hibiscus’ ability to substitute for it means you may still be able to use hibiscus tea.

If you keep hibiscus tea separated from Captopril by a few hours, then you could still get the benefits of both.

Hibiscus and Losartan

Hibiscus has the opposite effect on Losartan. In this case, it can increase your levels of the drug alongside having its own blood pressure-lowering properties.

Like all other medications, Losartan is removed by the liver through the set of detoxification enzymes it is most compatible with. Hibiscus tea slows the activity of some of the enzymes that process Losartan.

Hibiscus extracts are shown in lab research to slow the clearance of Losartan from the body, keeping the blood levels higher for longer periods. Another lab study found that hibiscus significantly increased the blood-pressure-lowering effects of Losartan, along with its blood levels.

Hibiscus also acts as a strong antioxidant, protects the heart from everyday wear and tear, and reduces levels of inflammatory uric acid. If you still want to enjoy hibiscus tea for these reasons, separate it from your Losartan dose by a few hours.

Hibiscus and Simvastatin

Simvastatin is prescribed to lower cholesterol, which indirectly lowers blood pressure by preventing the narrowing of the artery walls. Like Captopril, hibiscus tea could substitute for Simvastatin and speed its clearance from the body.

Hibiscus tea may both slow down the absorption of Simvastatin and speed up its detoxification. Its ability to delay Simvastatin absorption may be through an overall slowing of the digestive tract’s motility.

Lab research shows that hibiscus can reduce peak levels of Simvastatin by 18% and speed its clearance by around 44%. However, statins are known to cause a range of side effects, such as fatigue.

With more benefits coming from a lower level of the drug in your bloodstream, you may enjoy greater protection with fewer side effects when you take both together. If you need to take statins, it may once again be advisable to simply separate it from hibiscus tea for several hours.


Hibiscus has its own blood pressure-lowering benefits. However, it can raise or lower levels of certain medications for high blood pressure, depending on the specific drug.

Hibiscus tea and blood-sugar-lowering medication

Another benefit of hibiscus tea is that it can lower blood sugar levels. This adds to the effects of medication prescribed for high blood sugar, so it may lower it too much.

Hibiscus tea can slow the absorption of sugar into the bloodstream by inhibiting carbohydrate-digesting enzymes. It can also influence gene expression to prevent fat gain, which may contribute to insulin resistance.

Therefore, taking hibiscus tea alongside blood sugar-lowering medication may have an additive effect. This may lower your blood sugar too much and cause hypoglycaemia.

Hypoglycaemia leaves you feeling faint, unable to concentrate, or even aggressive – like being “hangry”, but for no apparent reason. Of course, it’s not safe to drive when you’re having an episode of hypoglycaemia.

Hibiscus tea and blood-sugar-lowering medication

For these reasons, you wouldn’t want to take hibiscus tea and medication to lower blood sugar together.

However, hibiscus tea does have a number of benefits for cardiovascular health, such as improved blood vessel flexibility and reduced blood pressure, which are even more important in diabetes. And the illness is a risk factor for heart disease. So, you had better ask your GP for advice instead of giving up the tea entirely.


Hibiscus tea can slow down the absorption of sugars after meals, creating an additive effect with medications used to lower blood sugar that may cause hypoglycaemia. Separating hibiscus from these medications is advisable.

When hibiscus tea changes the levels of your medication

Hibiscus extracts, including tea, can speed up or slow down the clearance of certain medications from the bloodstream. This is a much riskier type of interaction than additive effects, as there may be no alternative to the medication you’re prescribed.

Hibiscus tea may affect your levels of detoxification enzymes produced by the liver to remove medications, environmental toxins and metabolic waste.

Hibiscus may change the levels of Chloroquine

One of the medications that hibiscus tea may change the levels of is the anti-malarial drug, Chloroquine.

Taking hibiscus tea with Chloroquine can reduce the effect of the drug, as hibiscus tea can reduce the absorption of Chloroquine into the bloodstream.

In a clinical study, healthy volunteers drinking hibiscus tea had their blood levels of Chloroquine fall to around one-third of normal. Instead of 7.52 points, they only had 2.16 points on a concentration to time curve. These results were seen when the participants took Chloroquine with hibiscus tea, so it may be safe to separate them by several hours too.

It may not seem important to you right now, but taking anti-malarial drugs such as Chloroquine is necessary if you are travelling to a country with the disease.

International tourism is returning, and if you want to visit a tropical country such as Costa Rica, you may need to take Chloroquine or a similar drug.

Hibiscus can interfere with Voltaren

Another medication that hibiscus can interfere with is Voltaren, also known as the NSAID diclofenac.

Hibiscus can reduce your levels of key detoxification enzymes, including those your liver uses to process Voltaren. As a result, your body may hold onto the medication for longer, increasing its effects (and risk for toxicity).

A trial from Nigeria testing the effects of hibiscus on diclofenac levels only had to use a local commercial preparation of the tea to get significant results. After drinking hibiscus tea, volunteers only excreted 0.52ug of unchanged diclofenac in their urine, compared to 0.9ug in the control group.

The consequences were not explored, but this means that, once again, it is best to separate hibiscus tea from Voltaren by several hours.

Hibiscus and Tylenol

What’s more, hibiscus tea may speed up the clearance of acetaminophen (Tylenol) from the body.

Like diclofenac, Tylenol is another common painkiller used to treat headaches, hangovers and other minor issues.

Hibiscus’ ability to reduce levels of liver detoxification enzymes also affects acetaminophen. Strangely, other research shows that hibiscus speeds up the detoxification of the drug.

Another Nigerian study on commercially available hibiscus tea found that, while concentration over time wasn’t affected, the elimination rate was.

What this means for you is that the effects of acetaminophen may wear off faster, so hibiscus tea should be kept separate from Tylenol.


Through acting on specific liver enzymes, hibiscus tea may speed up or slow down the clearance of certain drugs or reduce their concentrations in the body.

Who should take hibiscus tea?

Hibiscus tea has a number of health benefits, including improved blood sugar control, easier weight loss, and as a refreshing antioxidant supplement. If it’s safe for you, go for it!

Who should take hibiscus tea

Drinking hibiscus tea may benefit your metabolic and cardiovascular health, including as a weight loss aid.

As a herbal medicine, hibiscus tea is suitable for people with:

  • Mild high blood pressure
  • Mildly elevated cholesterol or triglycerides
  • Mildly high blood sugar.

By “mild”, we mean your condition is not serious enough to require medication, and you are seeking natural remedies to prevent a level of severity that requires your medication and significantly impairs your quality of life.

Do not, however, suddenly replace your medication with hibiscus tea (or any other herbal remedy) without support from your doctor. Only begin to reduce the dose or eliminate medication entirely when you have the all-clear and a plan to safely come off it.

Other uses for hibiscus tea that prevent the need for medical attention later are:

  • As a weight loss aid, to promote fat-burning, prevent weight gain, and reduce the absorption of dietary fat
  • As a diuretic, which assists in weight loss when there is water retention.
  • As a substitute for sugary drinks, its tart, somewhat sweet flavour can make it a suitable replacement for fruit juices and soft drinks. This may indirectly protect you against the metabolic issues caused by chronically high sugar intake.
  • As an antioxidant supplement, in order to protect your cells and tissues from everyday damage.


Hibiscus tea may be right for you if you have mild cardiovascular issues, e.g. high blood pressure, blood sugar, triglycerides or cholesterol, or if you want to lose weight.

Who shouldn’t take hibiscus tea?

On the other hand, there are situations where hibiscus tea is not safe at all, or its safety is unclear. For example, if you are taking any of the medications we described above, you should avoid drinking hibiscus tea or keep it separated. There is also a chance that hibiscus tea is unsafe during pregnancy.

Hibiscus tea may not be recommended during pregnancy or breastfeeding because of its potential effects on hormonal pathways, such as oestrogen and prolactin. Our bodies grow and develop at a much faster rate before birth than at any time during our lives, so what we are exposed to then may impact us for life.

There is a theoretical risk that hibiscus tea may cause miscarriage in early pregnancy. Trials involving young women who have irregular, sparse periods (oligomenorrhoea) suggest that hibiscus tea may help to make them regular again.

However, whether or not hibiscus tea is safe during pregnancy still has no direct research, apart from animal studies suggesting a higher risk of miscarriage.

Evidence is lacking over whether or not hibiscus tea is safe during breastfeeding too. However, hibiscus is safe for children to enjoy, and breastfeeding mothers in some parts of the world use its seeds in an attempt to boost milk production. It has been used for many years in Africa as a traditional drink by people of all ages.


Alongside the potential risks, if you require medication for high blood pressure or cholesterol, hibiscus tea may not be suitable in pregnancy. It may affect the functions of oestrogen, potentially promoting menstruation.


Hibiscus sabdariffa is an amazing herbal tea, but there are some situations where it cannot be safely used. These include taking them at the same time as medication for high blood pressure or blood sugar, as it has an additive effect.

Additionally, hibiscus tea may speed up the clearance or reduce the absorption of certain medications, such as Chloroquine or Voltaren. Always check with your doctor before taking this herbal tea if you are on medication.