Sea moss is one of 2026’s biggest health food trends: Experts explain what it is and who SHOULDN’T be tucking into a jar of slimy algae

As unappetising as it sounds, sea moss – a type of red seaweed – is being hailed as the latest ‘superfood’ by wellness gurus and celebrities.

It is typically harvested from the sea, or increasingly grown in controlled pools, before being processed into gels, powders and gummies.

These are then added to drinks or sold as daily health boosters.

The most common variety used in supplements is known as Irish moss, a species of red algae.

On social media, it is promoted as a daily health staple, with claims it provides all the essential nutrients the body needs and leaves skin looking fresher and clearer than ever.

But how much of that is actually true?

Registered dietitian Nichola Ludlam-Raine believes people should tread with caution.

‘It’s gained popularity via social media as a ‘superfood’, but while it contains iodine and some fibre, most health claims about sea moss are overhyped and not backed by strong human evidence,’ she tells the Daily Mail.

What is in sea moss?

Typically consumed as a gel – and, as Kim Kardashian once suggested, blended into smoothies – sea moss is a source of many nutrients.

In its natural form it is suitable for vegans, is gluten–free, and provides various types of vitamin B – which keeps the nervous system healthy – as well minerals including calcium, iodine, potassium, sodium, iron, magnesium and zinc.

A typical serving of plain sea moss – two tablespoons – contains around 5 calories,  7mg of sodium, 1g of carbohydrates and little to no sugar, fat or protein.

It may also provide small amounts of soluble fibre, which can support healthy gut bacteria and boost digestive health.

However, some supermarket–bought versions may include added sugar, flavourings or preservatives, which could make it unhealthier.

What does sea moss do to your body… and can it help you lose weight?

Thanks to its mineral content, sea moss may offer plenty of health benefits.  

Calcium supports strong bones, teeth and muscles, while iron plays a key role in maintaining energy levels and helping to prevent fatigue.

Magnesium has been linked to muscle relaxation and healthy nerves, and zinc helps the immune system.

Sea moss is also full of carrageenan, a compound that may help promote feelings of suppressed hunger, though evidence for weight loss itself is limited.

Furthermore, it contains high levels of vitamin A, which is good for promoting healthy skin.

It does, however, contain sodium – which is found in salt and generally should not be consumed in excess as part of a healthy diet – and can be high in iodine, meaning it may not be suitable for everyone.

Ms Ludlam-Raine says: ‘It may contribute small amounts of nutrients and soluble fibre for gut health, but there’s no robust evidence it directly causes weight loss beyond any minor impact on fullness.’

Is it safe to take sea moss every day… and who should avoid it?

Ms Ludlam-Raine advises people to be careful when consuming sea moss daily due to its high iodine content.

Just one tablespoon of sea moss gel can contain between 56 and 100 micrograms of iodine, which is equivalent to roughly 37 to 65 per cent of an adult’s recommended daily intake.

The nutritionist continues: ‘Too much iodine can disrupt thyroid function; regular use isn’t advisable for those with thyroid conditions, and excessive amounts may lead to iodine excess and potential side effects.’

‘I wouldn’t advise my pregnant or breastfeeding patients take it either and would suggest those with medical conditions or who take prescribed medications should speak to a pharmacist first.’

What are the side effects of sea moss?

In addition to concerns for those with thyroid conditions, sea moss may also cause digestive issues such as bloating, nausea and diarrhoea due to its fibre content.

Some people may also experience reactions, particularly those sensitive to iodine. People with allergies to seaweed or shellfish are also generally advised to avoid it.

Sea moss can also absorb heavy metals from the water it grows in, depending on where it is harvested. 

Boots Pharmacy say that anyone who experiences ‘gut upset, a mild allergic reaction or are worried about heavy metal contamination or thyroid health, stop using it and see your GP or call NHS 111’.

Overall, it is recommended that you consult your GP or pharmacist before taking sea moss, as its effects can vary from person to person.