Do lactase tablets work?
They can, for some people. Take one just before dairy and it may cut or stop the bloating. But a tablet only helps if lactose is the cause. A two-week test can show you.
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Do lactase tablets work?
For some people, yes. The NHS says a lactase supplement taken before food or drink with lactose may reduce or prevent symptoms.
Lactose is the sugar in milk. Lactase is the enzyme that breaks it into smaller sugars your gut can absorb. Most lactose intolerance happens because your body doesn’t make enough lactase.
Think of lactase as scissors. Short on scissors, the uncut sugar moves on to your large bowel. Bacteria there feed on it, and you get the wind and bloating.
Short on lactase, milk sugar reaches your bowel uncut
- 1
You have dairy
Milk, yoghurt or ice cream all carry lactose.
- 2
Too little lactase
Some lactose passes on undigested.
- 3
Bacteria feed on it
In the large bowel this can cause bloating, wind, pain and diarrhoea.
- 4
A tablet adds lactase
Taken with the dairy, it can help you digest the lactose.
Sources: Allergy UK; NHS
A tablet brings its own scissors. So it only helps if it meets the lactose in your gut. That’s why you take it with the dairy, not hours later.
Allergy UK adds that response varies from person to person. Try it at one meal and see how you feel.
How much lactase enzyme, and when?
Look for the dose in FCC units on the pack. FCC units measure how strong the enzyme is. UK rules only let a supplement say lactase improves lactose digestion if it gives at least 4500 FCC units, taken with each meal that has lactose.
Lactaid pills, chewable tablets and drops all contain lactase. Check the label for FCC units and follow the maker’s instructions.
| 400 ml of milk with | Symptom score (higher is worse) |
|---|---|
| A dummy (placebo) | 3.7 |
| Lactase added 5 minutes before | 0.96 |
| Lactase added 10 hours before | 0.36 |
Source: Montalto et al, 2005
That trial of 30 adults with lactose intolerance found no side effects. The enzyme went into the milk, not into a swallowed tablet. Giving it longer to work helped most.
Lactose-free milk does the same job before you drink it. Its lactose is removed or broken down, often with lactase.
If milk is your main trigger, try lactose-free milk instead of a tablet.
Is lactose really the cause?
Bloating after a latte doesn’t prove it. Allergy UK says symptoms can overlap with other conditions. And in some people, lactose intolerance is caused by another condition, such as coeliac disease.
The two-week test for adults
- 1
Two weeks low lactose
Follow a strict low-lactose diet. Lactose-free milk and yoghurt are fine.
- 2
Watch your symptoms
Note whether the bloating and wind ease.
- 3
Bring lactose back
Bring dairy back slowly, starting with small amounts of lower-lactose foods like yoghurt. See if symptoms return.
- 4
Read the result
Symptoms back? Lactose intolerance is likely. No better at all? It’s unlikely.
Source: Allergy UK
That last step tells you if a tablet is worth buying. If two weeks off lactose changed nothing, a lactase tablet is unlikely to help.
Either way, a GP can help, as symptoms can overlap with other conditions. They may suggest blood tests or a breath test. Read what a coeliac blood test or a blood test for bloating can check.
For a child, don’t cut dairy without a GP or dietitian’s advice.
Do probiotics help lactose intolerance?
Maybe, but only some kinds. A 2005 review found probiotics in general did not ease symptoms in adults. It said some types (strains) and doses may work.
A 2020 review saw an overall positive link, tied to specific strains and amounts. But its studies varied a lot. A wider review called the probiotic evidence not enough to go on.
So a lactase tablet has the firmer case. If you still want to try a probiotic, read which probiotics help bloating first.
How much dairy can I have?
Often more than you think. A review of trials in people with lactose intolerance found most adults handle 12 to 15 g of lactose, about a cup of milk. Allergy UK says most people can manage small amounts, though it varies.
| Higher lactose | Lower lactose (many people manage small amounts) |
|---|---|
| Milk | Lactose-free milk |
| Soft cheese, like cottage or cream cheese | Hard cheese, like Cheddar, Parmesan or Edam |
| Ordinary yoghurt | Well-fermented yoghurt and kefir |
| Ice cream, custard, milkshakes | Butter |
Source: Allergy UK
Five ways to eat dairy with less trouble
- Take a lactase tablet just before food or drink that has lactose.
- Swap ordinary milk for lactose-free milk, which has similar calcium.
- Choose hard cheese, like Cheddar, over soft cheese.
- Pick plant drinks that are fortified with calcium.
- Check labels for milk, which pre-packed foods must highlight. Lactic acid has no lactose.
Sources: Allergy UK; NHS
Aim for around three portions of dairy or calcium-fortified swaps a day. Can’t manage that? Read about calcium supplements.
Lactose can also be in some protein shakes, breads and sauces. See dairy-free protein for other options.
Some medicines contain lactose, but usually too little to cause symptoms. Never stop or change a prescribed medicine without your prescriber.
When to speak to a GP
Lactase tablets may ease symptoms. They don’t find the cause. See a GP if you have symptoms of lactose intolerance and:
- Your symptoms keep coming back and often happen after eating, or you’ve been losing weight without trying.
- Your poo has changed for 3 weeks, such as looser poo, pooing more often or constipation.
- You’ve had blood in your poo, or tummy bloating and discomfort, for 3 weeks.
- Call 999 if your lips, mouth, throat or tongue suddenly swell, or your throat feels tight. The same goes if you’re breathing very fast, or struggling to breathe or swallow. Also call if skin, tongue or lips turn blue, grey or pale, or you suddenly feel very confused, drowsy or dizzy. Call too if someone faints and can’t be woken, or a child is limp, floppy or not responding like they normally do.
Those 999 signs point to a serious allergic reaction, not lactose intolerance. Intolerance doesn’t involve the immune system. Think it could be an allergy? Read about allergy blood tests.