Punarnava: Benefits, Uses, Safety & Side Effects

Punarnava is an Ayurvedic herb. Its botanical name is Boerhavia diffusa, and it belongs to the Nyctaginaceae family. In English it is sometimes called spreading hogweed. It is a low, spreading plant with small pink flowers, and it grows widely across India.

The name punarnava means "the one that renews the body". Ayurveda groups it among rasayana medicines, which are used with the aim of restoring health and vitality, and it has been part of Indian practice for centuries.

The root is the part most often used. The leaves, stems and the whole plant also go into preparations, and in parts of Odisha the leaves are cooked and eaten as a vegetable.

In India you rarely meet punarnava by itself. It usually comes inside an Ayurvedic product — a churna (powder), tablet, capsule or syrup — or in classical formulations such as Punarnavadyarishta, Punarnavasava, Punarnava guggulu, Punarnavadi kvatha churna and Punarnavadi mandura. Many of these contain other herbs as well, and some contain mineral or metal ingredients.

One caution about identity: punarnava has a long history of being confused with a different plant, Trianthema portulacastrum, which looks similar and is also sold as punarnava. That is one more reason to look for the botanical name Boerhavia diffusa on the label.

What is in it

Punarnava contains a large number of plant compounds. The ones studied most are:

• Rotenoids — Boeravinones A to J
• Alkaloids — Punarnavine
• Phenolic compounds — Punarnavoside, boerhavic acid
• Flavonoids — Quercetin, kaempferol
• Lignans — Liriodendrin
• Steroids — Beta-ecdysone, boerhavisterol

Different parts of the plant contain different compounds in different amounts, and how a product is made changes what ends up in it. So the list above is not a description of what a particular bottle contains.

In traditional Ayurvedic practice, punarnava is used mainly for fluid retention and swelling, including dropsy and ascites — fluid building up in the abdomen.

It also appears in preparations for liver complaints and jaundice, and traditional practitioners have used it for anaemia, joint pain and inflammation, and intestinal worms.

Every one of those is a traditional use, described in classical texts and reported by practitioners. None is a finding from a human trial, so a traditional use is a starting point for research rather than proof that the herb works.

The short answer: the benefits claimed for punarnava come mainly from traditional Ayurvedic use and from laboratory and animal studies. Only a few small studies have been done in people, and they do not settle whether it helps. It is fair to describe the evidence as early, not proven.

Here is what the research behind each common claim actually shows.

• Passing more urine (diuretic effect) — Root extract increased urine output in rats, and a diuretic compound called punarnavine was isolated from the root. No human trials.
• Protecting the kidneys — Less kidney damage in rats given gentamicin or cisplatin. Animal studies only.
• Protecting the kidneys, with another herb — A punarnava plus Tinospora cordifolia combination reduced kidney injury from diclofenac in rats. The result cannot be credited to punarnava alone.
• Protecting the liver — Lower liver enzymes and bilirubin in rats with paracetamol, alcohol or chemical liver injury, and in liver cells grown in the laboratory. No human trials.
• Lowering blood sugar — Lower blood sugar and improved cholesterol levels in diabetic rats. Animal studies only.
• Easing inflammation — Less inflammation and less oxidative damage in laboratory and animal models. No human trials.
• Jaundice, swelling, anaemia, joint pain, worm infestation — Described in classical Ayurvedic texts and by traditional practitioners across India. Traditional use.

What the studies in people show

• A study in 25 people with diabetic kidney disease found that six months of punarnava reduced protein in the urine, but the fall was not statistically significant. Ramipril, the standard medicine used in the same study, reduced it significantly.
• A study at an Indian Ayurveda hospital followed 67 people with chronic kidney failure for two months. One group received standard medical treatment, one received Ayurvedic treatment, and one received Ayurvedic treatment plus a multi-herb tablet called Punarnavadi compound. The group on standard medical treatment did better on more measures than the Ayurvedic groups. Because that tablet was taken along with several other Ayurvedic medicines, its results cannot be credited to punarnava.

How punarnava is thought to work

The way it acts in the human body is not established. What is known comes from laboratory work:

• The diuretic effect seen in animals is linked to compounds in the root, including the alkaloid punarnavine.
• The most common explanation offered for the organ protection seen in animal studies is antioxidant activity — plant compounds such as flavonoids and phenolics scavenge free radicals, the unstable molecules that damage cells.
• In liver cells grown in the laboratory, punarnava compounds reduced the damage caused by toxic chemicals.

What punarnava is not

• It is not a treatment for kidney failure, liver disease, heart failure or any other serious condition. Using it instead of the treatment your doctor has prescribed can be harmful.
• It is not a cancer treatment. Some laboratory studies have tested punarnava extracts against cancer cells, but this is very early research done in cells and animals. It does not show that punarnava can treat or prevent cancer in people, and it is not a reason to delay or refuse cancer treatment.
• It is not a safe way to deal with unexplained swelling. Swelling in the legs can be caused by problems with the kidneys, liver or heart, or by a blood clot. A herb that makes you pass more urine may make the swelling look better without treating the cause, and that delay can be dangerous.

Punarnava comes as a powder, tablet, capsule, syrup or decoction (kadha), and as an ingredient in classical Ayurvedic formulations.

The form matters less than these points:

• There is no standard, proven amount of punarnava for people. The quantities described in traditional texts vary widely and are not a medical dose, and amounts used in animal studies do not apply to humans.
• The amount printed on a pack applies only to that product. Two products labelled "punarnava" can contain different amounts, different plant parts, and other herbs.
• Use it only in the amount a registered Ayurvedic practitioner or your doctor advises — see the FAQs below on how long to take it.
• Store it as the label instructs, out of reach of children.
• If you miss a dose, take it when you remember unless the next one is nearly due. Do not take two doses to catch up.
• Follow the label or your practitioner on whether to take it with food.

No one can give you a complete list of side effects, because punarnava has not been studied in people for long enough to produce one. Most of what is known comes from animal experiments.

• In animal studies it has a wide safety margin. Rats given punarnava root extract showed no harmful effects at the doses tested, and the oral lethal dose in mice and rats was above 2,000 mg per kg of body weight. Short animal studies cannot tell you what months of daily use does to a person, or how the herb behaves alongside other medicines.
• Punarnava increases urine output in animals. If it does the same in you, you will pass more urine. Losing too much fluid or salt is a possible risk, especially if you also take a water tablet or a blood pressure medicine.
• Effects on fertility were seen in female rats. Higher doses reduced ovarian weight and disturbed the oestrous cycle, and rats given a high dose produced no litters. It is not known whether this happens in women. It is the main reason punarnava is not advised in pregnancy or when you are trying to conceive.
• Harm can come from the product rather than the herb. Ayurvedic medicines have been found to contain heavy metals above safe limits, so a problem you notice may have nothing to do with punarnava itself.

Avoid driving or operating machinery if you feel dizzy or unwell after taking it. If you notice anything new or unusual after starting it, stop and speak to a doctor rather than continuing.

Some groups should not take punarnava at all:

• Pregnant women. Animal studies show effects on the female reproductive system, and there is no safety information for use in pregnancy.
• Women trying to conceive. The same animal findings apply, and there is no human data to reassure you.
• Breastfeeding women. There is no safety information for breastfeeding.
• Children. Not advised — see the FAQ below.

These groups do not have to avoid it, but should not take it without medical advice first. One situation needs planning ahead:

• People with kidney disease, including those on dialysis. A herb that increases urine output can disturb fluid and salt balance, and how punarnava affects an already damaged kidney is not established.
• People with heart disease, heart failure or high blood pressure. Diuretics and medicines that widen blood vessels are used in careful balance in these conditions, and adding a herb with similar effects can upset that balance.
• People with diabetes on insulin or tablets. Animal studies show punarnava lowers blood sugar, so adding it could push your sugar too low.
• Older adults. Ask your doctor before starting any herbal product.
• People with liver disease. Punarnava is not an established treatment for liver disease, and self-treating a damaged liver is not advisable.
• Before surgery. Stop herbal products ahead of surgery and tell the surgical team what you have been taking. This is a timing precaution, not a permanent contraindication.

Yes, it may. No study in people has measured these interactions, so the information below comes from laboratory and animal findings, and from how similar medicines behave when combined.

• Water tablets (diuretics) such as furosemide — punarnava has diuretic activity in animals. Taken together, they could remove too much fluid and salt.
• Blood pressure medicines — punarnava extracts widen blood vessels and inhibit an enzyme called ACE in studies. Combined, blood pressure could fall lower than intended.
• Diabetes medicines and insulin — the two together could lower blood sugar more than either would alone.
• Sedatives and anti-anxiety medicines such as benzodiazepines and barbiturates — punarnava extracts have shown anticonvulsant activity in mice, and may add to their calming effect.
• Tamoxifen and simvastatin — quercetin, a compound found in punarnava leaves, increased the amount of both medicines that entered the body in animal studies. Whether the same happens in people is not known.

The practical point: tell every doctor and pharmacist you see about any Ayurvedic product you take, including anything you bought yourself "for general health". People often do not mention them, and that is when interactions get missed.

Because punarnava is sold as an Ayurvedic medicine rather than a standard drug, the product around it deserves as much attention as the herb.

• Ayurvedic medicines are licensed in India under the Drugs and Cosmetics Act, 1940 and the Rules of 1945, through state licensing authorities. For a patent or proprietary Ayurvedic medicine, those rules ask for a textual rationale and a pilot study rather than the clinical trial evidence a modern medicine needs. A 2016 analysis argued that this lets such products reach the market without proof that they work, and the recommendation to require that proof has not been put into effect. The position may change, because these rules have been under amendment.
• Indian law prohibits advertisements claiming that a product can diagnose, treat, prevent or mitigate any of the conditions listed in the Drugs and Magic Remedies (Objectionable Advertisements) Act, 1954 and the rules made under it. That list includes cancer, diabetes, obesity and asthma. If a punarnava product makes a claim of that kind, the claim is against the law rather than proof that the product works.
• Contamination is a real concern. A 2022 study tested 42 over-the-counter Ayurvedic products bought from licensed shops in Chandigarh. Heavy metals were detected in every product, and roughly three in four had mercury, arsenic or lead above the limits set for herbal medicines. Only about one in four labels mentioned any metal at all.
• Reports of adverse events linked to Ayurvedic medicines have been increasing in the medical literature. The World Health Organization has published guidance on why monitoring the safety of traditional medicines matters.

What you can do:

• Buy from a licensed Ayurvedic shop or a pharmacy you trust, and keep the pack.
• Read the ingredient list. If it names a metal or mineral ingredient, ask what it is before you take the product.
• Check that the label names the plant properly, as Boerhavia diffusa or punarnava, rather than only a marketing name.
• Stop and get medical advice if you feel unwell.

Do not use punarnava to manage swelling or any other symptom on your own. Get medical advice if:

• One ankle, foot or leg is swollen and you do not know why.
• The swelling is severe or painful, or came on suddenly.
• You also have swelling in your face or abdomen.
• The swollen area is red or hot to the touch, or you have a fever.
• Both legs or ankles are swollen and it is not improving, or you already have been diagnosed with a heart, kidney or liver condition.
• You have diabetes and your feet, ankles or legs are swollen.
• You feel short of breath, have chest tightness or pain, or your heartbeat feels noticeable.

Get emergency help — call 112, or an ambulance on 108 — if you are struggling to breathe, have chest pain, or feel faint, confused or very unwell. If you or someone else has taken too much of an Ayurvedic product, go to the nearest hospital emergency department and carry the pack with you.