Ashwagandha (Withania somnifera) is one of the most important herbs in Ayurveda, where it has been used for centuries as a “rasayana”, a tonic for strength and resilience. It’s now one of the best-selling supplements in the US. Here’s what the evidence shows, and how to use it safely.

What people use it for

• Everyday stress and feeling “wired but tired”
• Sleep quality
• Energy, stamina and recovery from exercise

What studies show

• Stress and anxiety: several small clinical trials found that people taking ashwagandha root extract for 6 to 8 weeks reported lower stress scores and lower levels of the stress hormone cortisol than people taking a placebo.
• Sleep: some studies suggest modest improvements in how quickly people fall asleep and how well they sleep.
• Exercise: a few studies in active adults found small gains in strength and endurance.

Most studies were small and short, often lasting 8 to 12 weeks, so the results are promising but not conclusive. Ashwagandha isn’t a treatment for anxiety disorders, depression or insomnia. If those affect your daily life, talk to a doctor.

How to take it

• Studies typically used 250 to 600 mg of root extract a day. Follow the directions on your product.
• Take it with food to reduce stomach upset. Many people take it in the evening.
• Give it 4 to 8 weeks before judging the effect.
• Buy from a reputable brand, such as Himalaya Ashvagandha.

Side effects

• Common: upset stomach, diarrhoea, nausea and drowsiness
• Rare but serious: liver injury. Stop taking it and see a doctor straight away if you notice yellow skin or eyes, dark urine, pale stools, itching or pain in the upper right tummy.

Who should avoid it

• Pregnant women: high doses may cause miscarriage. Avoid it if pregnant or trying to conceive, and while breastfeeding.
• People with thyroid conditions: it may raise thyroid hormone levels
• People with autoimmune diseases such as rheumatoid arthritis, lupus or MS, as it may stimulate the immune system
• People with liver disease
• Anyone due to have surgery in the next 2 weeks, because it may add to the effects of anaesthesia

Drug interactions

Check with a doctor or pharmacist before taking ashwagandha if you take:

• Sedatives or sleeping tablets
• Thyroid medicine
• Diabetes or blood pressure medicines, as it may lower blood sugar and blood pressure
• Immune-suppressing medicines

Frequently asked questions

How long does ashwagandha take to work?

Most studies looked at results after 6 to 8 weeks of daily use.

Can I take ashwagandha every day?

Studies have used daily doses for up to about 3 months. Long-term safety isn’t well known, so talk to your doctor if you plan to take it for longer.

Should I take ashwagandha in the morning or at night?

Either works. If it makes you drowsy, take it in the evening.

Does ashwagandha help with weight loss?

Not directly. By helping with stress and sleep, it may support healthy habits. See our guide to Ayurvedic herbs for weight loss and sleep and weight loss.

This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Supplements are not evaluated by the FDA to diagnose, treat, cure or prevent any disease.

Permethrin 1% creme rinse, sold in the US as Nix and other brands, is one of the most widely used over-the-counter treatments for head lice. Used correctly, alongside careful combing, it clears many cases. Here’s how to get the best result, and what to do if lice keep coming back.

How it works

Permethrin is an insecticide that attacks the nervous system of lice. It kills live lice and some eggs (nits), and leaves a small amount on the hair that can keep working for several days.

Who can use it

• Adults and children aged 2 months and over, following the label
• Babies under 2 months, and anyone pregnant or breastfeeding: ask a doctor first
• Don’t use it if you’re allergic to chrysanthemums or ragweed, or if the scalp is broken or infected

How to use permethrin 1%, step by step

1. Wash the hair with a shampoo that has no conditioner, then towel dry. Conditioner can coat the hair and stop the treatment working.
2. Shake the bottle and apply enough to soak the hair and scalp, especially behind the ears and at the back of the neck.
3. Leave it on for 10 minutes, then rinse with warm water over a sink, not in the shower, to limit skin contact.
4. Comb through with a fine-toothed nit comb, section by section, to remove dead lice and eggs.
5. Don’t wash the hair again for 1 to 2 days.
6. Check again and repeat on day 9 if you find live lice, to kill any lice that have hatched since.

Why it sometimes fails

In many parts of the US, head lice have become resistant to permethrin. If you still find live, moving lice 8 to 12 hours after treatment, or after the second treatment, the lice may be resistant. Repeating permethrin again and again won’t help.

Alternatives if permethrin doesn’t work

• Ivermectin 0.5% lotion (Sklice), available over the counter in the US since 2020. A single 10-minute treatment usually works without combing. See our guide to head lice treatment.
• Spinosad or malathion lotion, which need a prescription
• Wet combing alone with conditioner and a nit comb every 3 to 4 days for 2 weeks, which needs no chemicals

Around the home

• Wash pillowcases, hats and towels used in the last 2 days in hot water, or seal them in a bag for 2 weeks
• Soak combs and brushes in hot water for 10 minutes
• Check everyone in the home, and only treat people who have live lice
• There’s no need for insecticide sprays on furniture or carpets

Side effects

Mild itching, redness or tingling of the scalp is common and usually fades. Itching can also continue for a while after lice are gone, as a reaction to the bites. Wash off and get help if you notice swelling, a rash or trouble breathing.

Frequently asked questions

Is permethrin 1% the same as permethrin 5%?

No. The 1% creme rinse is for head lice and is sold over the counter. The 5% cream is a prescription treatment for scabies, which is applied to the whole body. See scabies symptoms and treatment.

Can my child go to school after treatment?

Yes. US health organisations advise that children don’t need to miss school because of head lice.

Do I need to treat the whole family?

Check everyone, but only treat people who have live lice.

More in our Lice and Parasites guide: all our articles on this topic in one place.

This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Always read and follow the label.

Pinworms are the most common worm infection in the US, especially in children aged 5 to 10. The good news is that they’re easy to treat. In the US, the main over-the-counter treatment is pyrantel pamoate, sold under names such as Pin-X and Reese’s Pinworm Medicine. Here’s how to use it properly.

How pyrantel works

Pyrantel paralyses adult pinworms in the gut so they lose their grip and pass out in the stool. It acts mainly inside the bowel, and very little is absorbed into the body.

Who can use it

• Adults and children aged 2 and over, following the label
• Children under 2 or weighing under 25 lb (about 11 kg): ask a doctor first
• Pregnant or breastfeeding: ask a doctor before use

How to take it

• Dose is based on body weight. Use the weight chart on the pack, and the measuring cup or spoon supplied. Don’t guess.
• It’s a single dose, taken at any time of day, with or without food. The liquid can be mixed with milk or juice.
• A second dose after 2 weeks is commonly recommended by doctors, because pyrantel doesn’t kill eggs, and newly hatched worms can restart the infection. Check with your doctor or pharmacist.

Treat the whole household

Pinworm eggs spread easily on hands, bedding, towels and toys, so doctors often recommend treating everyone in the home at the same time, even if they have no symptoms. Ask your doctor about anyone under 2 or pregnant.

Stop pinworms coming back

• Wash hands with soap after using the toilet and before eating, and keep nails short
• Shower each morning to wash away eggs laid overnight
• Change underwear daily and wash pyjamas, bedding and towels in hot water
• Discourage nail-biting and scratching around the bottom
• Vacuum and wipe surfaces such as toilet seats and door handles

Possible side effects

Most people have none. Some get nausea, vomiting, tummy cramps, diarrhoea, headache or dizziness. Stop and see a doctor if you have a rash or anything that worries you.

When to see a doctor

• Symptoms don’t clear after the second dose
• The child is under 2, or the person is pregnant
• You’re not sure it’s pinworms. A doctor can confirm it with a simple “tape test”.
• Severe tummy pain, or worms seen in other places

Doctors may prescribe a different medicine, such as mebendazole or albendazole, if pyrantel isn’t suitable. Read more in our guide to pinworm symptoms and treatment.

Frequently asked questions

How fast does pyrantel work?

It starts working within a day, and the itching usually eases within a few days. Eggs can survive on surfaces for 2 to 3 weeks, so hygiene and the second dose matter.

Can I buy pyrantel without a prescription?

Yes, in the US it’s available over the counter for adults and children aged 2 and over.

Do pets spread pinworms?

No. Human pinworms only live in people, so you don’t need to treat your pets.

More in our Lice and Parasites guide: all our articles on this topic in one place.

This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Always read and follow the label.

Psyllium husk, known in India as isabgol, is the outer coating of seeds from the Plantago ovata plant. Most of the world’s psyllium is grown in India, and it’s the main ingredient in fibre supplements such as Metamucil. It’s one of the most studied and affordable fibre supplements available.

What psyllium husk does

Psyllium is a soluble fibre. When it mixes with water it forms a thick gel, which softens stool, slows digestion and helps you feel full.

Benefits with good evidence

• Constipation: it softens and bulks up stool so it passes more easily. It’s often the first thing pharmacists suggest.
• Diarrhoea: by soaking up excess water, it can also firm up loose stools.
• Cholesterol: taken daily, psyllium can lower LDL (“bad”) cholesterol by a modest amount. In the US, the FDA allows a heart-health claim for psyllium as part of a diet low in saturated fat and cholesterol.
• Blood sugar: taken with meals, it can reduce blood sugar spikes after eating.
• Feeling full: it may help you feel fuller and eat a little less, which can support weight management. See fibre for weight loss.

How to take it

• Start low: 1 teaspoon (about 3 to 5 g) once a day, and build up over 1 to 2 weeks to 1 to 2 doses a day. Follow the product label.
• Always mix with a full glass of water (at least 240 ml / 8 oz) and drink it straight away, before it thickens. Then drink plenty of fluids through the day.
• Take medicines 2 hours apart from psyllium, as it can reduce how well they’re absorbed.
• For feeling full, take it 20 to 30 minutes before a meal.

Side effects

• Wind, bloating and tummy cramps, especially at first. Building up slowly helps.
• Choking or blockage risk if taken without enough water. Never take it dry.
• Rarely, allergic reactions. Stop and get help if you have trouble breathing or swallowing, or a rash.

Who should check with a doctor first

• Anyone with difficulty swallowing, a narrowed bowel or a history of bowel blockage
• People with diabetes, as it can lower blood sugar after meals
• Anyone taking regular medicines, because of the absorption issue
• Children

See a doctor if

You have a sudden change in bowel habits lasting more than 2 weeks, blood in your stool, unexplained weight loss, or severe tummy pain.

Frequently asked questions

Is isabgol the same as psyllium husk?

Yes. Isabgol is the Hindi name for psyllium husk.

Can I take psyllium every day?

Yes. It’s safe for daily long-term use for most adults, as long as you drink enough water.

When is the best time to take psyllium?

Any time that suits you, keeping it 2 hours away from medicines. Before meals may help with fullness and blood sugar. At bedtime with water is common for constipation.

Does psyllium help you lose weight?

It may help a little by making you feel fuller, but it works best as part of a balanced diet with plenty of other fibre-rich foods.

Related: How long does Dulcolax take to work?

More in our Digestive Health guide: all our articles and products on this topic in one place.

This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Supplements are not evaluated by the FDA to diagnose, treat, cure or prevent any disease.

Berberine has become one of the fastest-growing supplements in the US, helped by social media posts calling it “nature’s Ozempic”. It’s a plant compound found in goldenseal, barberry and the Ayurvedic herb daruharidra (tree turmeric), and it has been used in Ayurvedic and Chinese medicine for centuries. Here’s what the evidence actually shows.

Is berberine really “nature’s Ozempic”?

No. Medicines like Ozempic and Wegovy (semaglutide) commonly lead to weight loss of around 15% of body weight in trials. Studies of berberine show much smaller effects. Berberine works differently, mainly by influencing how cells use sugar, and it doesn’t copy the appetite-suppressing hormone GLP-1 in the same way.

What studies show

• Weight: reviews of clinical trials suggest berberine may lead to a small extra weight loss of around 2 kg (4 to 5 lb) over several months, compared with a placebo.
• Blood sugar: the strongest evidence is for lowering blood sugar and HbA1c in people with type 2 diabetes or prediabetes.
• Cholesterol: some studies show modest reductions in LDL cholesterol and triglycerides.

Many studies were small, short or of mixed quality, so the results should be treated with caution.

How people take it

Studies typically used 500 mg two or three times a day with meals, up to 1,500 mg a day. Splitting the dose and taking it with food reduces stomach side effects. Follow the directions on the product, and talk to a doctor before starting.

Side effects

• Constipation, diarrhoea, wind and stomach cramps are the most common, especially at higher doses
• Low blood sugar, particularly if combined with diabetes medicine

Drug interactions: important

Berberine affects liver enzymes that break down many medicines. Talk to a doctor or pharmacist before taking it if you take:

• Diabetes medicines, including metformin and insulin
• Blood pressure medicines
• Blood thinners
• Ciclosporin or other immune-suppressing medicines
• Sedatives or any regular prescription medicine

Who should not take berberine

• Pregnant or breastfeeding women: it can harm a baby
• Babies and children
• People with liver disease

The bottom line

Berberine may help a little with blood sugar and weight, but it isn’t a replacement for diet, activity or prescribed treatment. It’s most worth discussing with your doctor if you have prediabetes or high blood sugar. For other approaches, see Ayurvedic herbs for weight loss, fibre for weight loss and weight loss medicines explained.

Frequently asked questions

How long does berberine take to work?

Studies on weight and blood sugar usually lasted 8 to 12 weeks or more. Don’t expect quick results.

Can I take berberine with metformin?

Only with your doctor’s agreement. Both lower blood sugar, and together they can cause low blood sugar or more stomach side effects.

Is berberine safe long-term?

Long-term safety beyond about 6 months isn’t well studied. Use it under a doctor’s guidance if you plan to take it for longer.

More in our Weight Management guide: all our articles on this topic in one place.

This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Supplements are not evaluated by the FDA to diagnose, treat, cure or prevent any disease.