What is Habb al-Qilqil (Karanjwa)?

Habb al-Qilqil is the hard grey seed of the thorny shrub Caesalpinia bonduc, known in English as fever nut or nicker nut. In Unani medicine it is a single drug, used mainly as a bitter remedy for fevers that come and go, for worms in the gut, and for painful periods.

The seed kernel is intensely bitter. It is usually taken as a small amount of powder, sometimes roasted first, and the leaf and bark are used in related traditional preparations.

Here is the plain verdict: this seed has a long and well documented place in Unani, Ayurvedic and Siddha practice, but almost all modern testing has been done in test tubes and in animals. Long traditional use tells you people valued it; it does not prove the seed works in humans, and that point is made once here rather than repeated in every section below.

How does Habb al-Qilqil (Karanjwa) work?

Nobody has shown clearly how this seed works in the human body, so what follows is a best guess from laboratory work.

The kernel is full of bitter compounds. Bitter plant drugs of this kind can irritate the gut lining, which may explain the traditional use against intestinal worms and the nausea some people report.

Animal studies report drops in blood sugar, lower fever and some anti-parasite activity in the test tube. These are early findings in rats, mice and dishes, not evidence of an effect in people.

What forms does Habb al-Qilqil (Karanjwa) come in?

Common forms include:

Roasted or raw kernel powder, the usual Unani form, taken by the pinch.

Kernel powder pressed into small pills, often combined with other drugs in compound Unani formulas.

Seed oil, used on the skin in traditional practice for joint pain.

Leaf or bark decoctions (boiled water extracts), used separately from the seed.

Capsules and powders sold online as 'Bonduc nut' or 'Latakaranja'. These are not tested for strength or purity in most countries.

Where it comes from:

The seed appears in classical Unani texts under the name Habb al-Qilqil and in Persian and Arabic pharmacy as a bitter, warming drug for intermittent fevers.

It is equally at home in Ayurveda and Siddha as Latakaranja or Karanjwa, and spread with trade across coastal Africa, South Asia and the Caribbean, where the floating seeds wash ashore.

Because the same seed is a named drug in several separate written traditions, its traditional standing is strong even though its modern test record is thin.

What does Habb al-Qilqil (Karanjwa) help with?

• Intermittent fevers, including malaria-type fever in traditional use: This is the seed's oldest and most famous use, and the reason for the English name fever nut. Laboratory work has found some activity against malaria parasites in the dish. There are no good human trials showing it treats malaria, and malaria is a life-threatening illness that needs tested medicine and a doctor.
• Intestinal worms: Unani and Ayurvedic practice both use the bitter kernel against worms in the gut. Test-tube studies on worms support the idea, but no published human trial shows it clears an infection. Modern deworming tablets are cheap, safe and proven, and are the sensible first choice.
• Painful or irregular periods: Traditional texts give the seed for period pain and for periods that have stopped. That second use is exactly why it is unsafe in pregnancy: it is described as a drug that stimulates the womb. Human evidence for period pain is absent.
• Poor appetite and sluggish digestion: Bitter drugs are given across many traditions to wake up appetite, and this seed is one of the most bitter. The effect is plausible and immediate for some people, but it has not been measured in a trial. Too much causes nausea instead.
• Joint pain (seed oil, used on the skin): The pressed seed oil is rubbed on aching joints in Unani and folk practice. This use rests on tradition alone. No human trial of the oil on skin has been published.
• High blood sugar (animal data only): Several rat and mouse studies report that seed extracts lower blood sugar. That is interesting but it is not human evidence, and it is also a warning: if you take diabetes medicine, adding this seed could push your sugar too low.

Which foods are rich in Habb al-Qilqil (Karanjwa)?

This is a medicinal seed, not a food. It is too bitter to eat as part of a meal and no food supplies its compounds.

What are the side effects of Habb al-Qilqil (Karanjwa)?

• Nausea
• Vomiting, especially on an empty stomach or at higher doses
• Stomach pain and cramping
• Diarrhoea
• Low blood sugar, with shakiness, sweating or confusion
• Skin irritation from the seed oil in some people
• Bleeding or cramping in pregnancy

Good to know:

Stomach upset is the common problem and it is dose-related: more seed, more nausea.

The two serious risks are low blood sugar (hypoglycaemia) in people already on diabetes medicine, and harm in pregnancy, because the seed is traditionally used to bring on periods.

Safety data in humans is sparse, so unexpected reactions cannot be ruled out. Stop at once if you feel unwell.

How much Habb al-Qilqil (Karanjwa) should you take?

• Recommended daily: There is no dose established by research. Any number you see comes from traditional practice, not from testing. Unani and Ayurvedic texts commonly give 0.5 to 2 grams of kernel powder a day, split into two doses, often roasted first to soften the bitterness. Start at the low end if you use it at all. The seed is strongly bitter and larger amounts cause vomiting rather than stronger benefit.
• Best time of day: Traditionally taken in the morning and again in the evening. For fever, older texts time doses before the fever is expected. None of this timing has been tested.
• With or without food: Take it with or just after food. On an empty stomach the bitter kernel is much more likely to cause nausea and stomach pain.
• Time to effect: Bitterness and any effect on appetite are felt within minutes. For anything else, no reliable timeline exists because no human trials have measured one.
• How long to take it: Traditional use is short and aimed at a problem, not taken every day for months. Two weeks is a sensible limit before you stop and think about whether anything actually changed. If your fever, worms or period pain have not settled in that time, the answer is a doctor, not a larger dose.