Digestive Enzymes: What They Do, Do Supplements Work and Who Needs Them (UK)

What are digestive enzymes?

Digestive enzymes are proteins made in the mouth, stomach, pancreas and small intestine that split food into molecules the gut can absorb. Each enzyme works on one type of food: amylase on starch, protease on protein, lipase on fat, and lactase on lactose, the sugar in milk. Supplements contain copies of these enzymes from plants, fungi, bacteria or pigs.

Most healthy people make enough of their own enzymes, apart from lactase, which many adults make less of after childhood. Alpha-galactosidase is the odd one out: humans don’t make it, which is why gut bacteria ferment bean sugars and produce wind. Bromelain comes from pineapple and papain from papaya.

For the wider picture on keeping your gut well, see our gut health guide and the ranked list of supplements for digestion.

Prescription digestive enzymes vs over-the-counter supplements

Prescription digestive enzymes, called pancreatic enzyme replacement therapy (PERT), are licensed medicines such as Creon for people whose pancreas can’t make enough enzymes. Over-the-counter digestive enzyme supplements are foods, not medicines, with much smaller and unregulated doses. One can’t stand in for the other, and PERT is never something to swap for a shop product.

• Who gets PERT: people with exocrine pancreatic insufficiency, for example from chronic pancreatitis, cystic fibrosis, pancreatic cancer or pancreatic surgery. The NICE pancreatitis guideline covers how it should be prescribed and explained.
• What’s in it: pancreatin, a mix of lipase, protease and amylase. NHS hospital guidance notes that all pancreatic enzyme products are made from pig pancreas.
• How it’s taken: with every meal, snack and milky drink, at a dose your team adjusts to the fat in the meal. It does nothing if taken without food.
• Signs it may be needed: the NHS lists very smelly poo that floats and is hard to flush, and losing weight without trying, among the symptoms of chronic pancreatitis.

In people who need it, PERT works: a 2017 review of 14 trials in chronic pancreatitis found it improved fat absorption and reduced digestive symptoms compared with placebo. If you take Creon or a similar medicine, ask your specialist team or pharmacist before adding any other enzyme product.

Do digestive enzyme supplements work?

Digestive enzyme supplements work for specific, diagnosed problems: lactase helps people with lactose intolerance digest milk sugar, and prescription pancreatic enzymes help people with pancreatic insufficiency absorb fat. For everyday bloating, indigestion or “better digestion” in healthy people, there’s little good evidence that broad enzyme blends make a difference.

The Beano-type trials were short and used test meals packed with beans, so they say little about day-to-day bloating. The American Gastroenterological Association’s 2023 expert review of bloating management focuses on finding the cause, diet changes and gut-directed treatments rather than enzyme blends.

Lactase and lactose intolerance: the one authorised claim

Lactase is the only digestive enzyme with an authorised health claim in Great Britain. The approved wording is “Lactase enzyme improves lactose digestion in individuals who have difficulty digesting lactose”. It applies only to food supplements giving at least 4,500 FCC units, taken with each meal that contains lactose.

The conditions also say people must be told that tolerance to lactose varies, and that they should seek advice on the role of lactase in their diet. So when you compare lactase products, check the FCC units on the label: below 4,500 per dose, the product can’t use the claim.

The NHS says taking a lactase supplement before food or drink containing lactose may reduce or prevent symptoms for some people. Lactose-free milk, which has lactase added during processing, is another route. Don’t cut foods out of a child’s diet without a GP’s advice. If you’re avoiding dairy, our dairy-free hot chocolate guide covers plant milks and what to check.

Digestive enzymes for bloating: what to try first

Digestive enzymes are unlikely to fix general bloating unless a specific food intolerance is the cause. The NHS advice for bloating starts with eating slowly, smaller meals, regular exercise, plenty of water and soluble fibre if you’re constipated, and cutting back on fizzy drinks, alcohol and foods that give you wind. A pharmacist can suggest simeticone.

• If constipation is behind it: fibre first. See foods that help constipation and psyllium husk, which has the strongest evidence of any fibre supplement.
• If it follows dairy: ask a GP about lactose intolerance, and try lactase with dairy meals.
• If it follows beans or lentils: alpha-galactosidase may cut wind after those meals, though the evidence is small.
• If it comes with pain and changes in your poo: it could be IBS, which a GP can diagnose. See our IBS guide.

Probiotics are a different thing (live bacteria, not enzymes); our probiotics guide covers where they help. If you feel wiped out after meals, read why am I tired after eating?, and for the magnesium angle, magnesium for bloating.

Digestive enzymes side effects and who should check first

Most enzyme supplements are well tolerated. The usual side effects are stomach upset, wind, nausea and loose stools. In the 125-person IBS trial, more people stopped alpha-galactosidase than placebo, mostly because of tummy pain and diarrhoea.

• Prescription enzymes: never change or stop your PERT dose, or add other enzymes, without your specialist team. Pancreatin comes from pigs, which matters if you avoid pork; talk to your team rather than stopping.
• Allergies: bromelain comes from pineapple and papain from papaya, so avoid them if you’re allergic to those fruits.
• Galactosaemia: alpha-galactosidase releases galactose, so people with this rare inherited condition should avoid it.
• Diabetes: ask your pharmacist first if you take medicines for diabetes, as some enzymes release sugars from food.
• Pregnancy, breastfeeding and children: little is known about most enzyme blends. Check with a GP, midwife or pharmacist first.

iIf you take any regular medicines, check with your GP or pharmacist before starting a digestive enzyme supplement.

When to see a GP about digestion

iSee a GP rather than reaching for digestive enzymes if digestive symptoms are new, persistent or come with warning signs. A GP can test for lactose intolerance, coeliac disease, IBS and pancreatic problems, and some causes need treatment that supplements can’t give.

• You feel bloated regularly, or keep feeling bloated after changing your diet.
• You’re losing weight without trying.
• You have blood in your poo.
• Your poo is pale, greasy, very smelly, floats or is hard to flush.
• Your bowel habits have changed and it hasn’t settled, for example looser poo or going more or less often than usual for you.

Get an urgent GP appointment or call 111 if bloating comes with vomiting, diarrhoea, constipation, tummy pain, a high temperature, a lump in your tummy, or if you can’t pee, poo or fart. Call 999 or go to A&E if you have a swollen stomach with sudden severe tummy pain, you’re vomiting blood or your vomit looks like ground coffee, or you’re struggling to breathe.