All Women's Blood Tests
Lactose Intolerance Risk Clinic test
Genetic risk · digestion

Lactose Intolerance Risk

Tests the two gene variants (C13910T and G22018A) that determine whether you keep producing lactase — the enzyme that digests the sugar in milk — into adulthood.

Price £120 £106.99
Covers 2 genes
Type Clinic visit · ~15 min
Book just this test
Blood sample for DNA analysis — taken at 44 Crawford Street, Marylebone
No preparation needed — you do not need to eat or avoid dairy beforehand.
Results explained by our clinical team
About this test

Everything you need to know about Lactose Intolerance Risk

Most mammals stop making lactase after weaning; many humans carry a genetic change that keeps it switched on for life. If you did not inherit that change, your ability to digest lactose falls through adulthood and milk, cream and soft cheese can cause bloating, cramps, wind and loose stools.

This test reads the two variants near the LCT gene — C13910T and G22018A — that control lactase persistence. Unlike a breath test or an elimination diet, it is not affected by what you ate yesterday and it distinguishes a genetic predisposition from a temporary intolerance after a stomach bug or alongside another gut condition.

What's measured

What's included

2 genes in this test

C13910T G22018A
Who it's for

Worth considering if

  • Bloating, cramps or loose stools after milk, ice cream or creamy food
  • Working out whether symptoms are lactose, or something else such as IBS or coeliac disease
  • Deciding whether to cut dairy long-term or just reduce it
  • A family history of lactose intolerance
Important: A genetic test describes inherited likelihood, not certainty, and is not suitable for everyone. Our clinical team talks it through with you before the sample is taken and explains the result afterwards, including when a conversation with your GP or a genetics service is the right next step.
What to expect

Your visit

1

Book online

Add this test — and any others — to your booking, pick a time at the clinic and pay online. No preparation needed — you do not need to eat or avoid dairy beforehand.

2

Your visit

About 15 minutes at 44 Crawford Street, Marylebone. Our clinical team takes your sample (blood sample for dna analysis) and answers any questions.

3

Results explained

The laboratory analyses your sample and your results are released to your secure account with a written explanation from our clinical team — and a call where something needs talking through.

Frequently Asked

Lactose Intolerance Risk — FAQs

What will the result tell me?
Whether your genes support lactase production into adulthood (lactase persistent) or not (predisposed to lactose intolerance). Many people with the non-persistent result can still tolerate small amounts of dairy — the test tells you the tendency, your body tells you the threshold.
Can lactose intolerance be temporary?
Yes. Gut infections, coeliac disease and other conditions can reduce lactase for a while. If your genetic result says you should tolerate lactose but you clearly do not, that points towards another cause worth investigating.
Is this a milk allergy test?
No. Cow’s milk allergy is an immune reaction to milk proteins and is a different condition. If you have ever had swelling, hives or breathing difficulty after dairy, tell us at your appointment.
Do I need to stop eating dairy before the test?
No. The result depends only on your DNA.
Where is the test done?
44 Crawford Street, London W1H 1JS — a short walk from Marylebone and Edgware Road stations. Your sample is taken at the clinic by our clinical team; you do not need to bring anything.
How long does the appointment take?
About 15 minutes. If you have booked several tests they are all done in the same visit.
Can I book several tests at once?
Yes. Use “Add to booking” on each test and then “Book” in the bar at the bottom — they go into one appointment and one payment. Home test kits are ordered separately, because they are posted to you.
How do I pay, and can I cancel?
Pay online when you book — by card or bank transfer — or at the clinic where that option is offered. You can cancel or reschedule up to 24 hours before your appointment for a full refund.
How do I get my results?
Results are released to your secure account and explained by our clinical team in a written summary, with a call where something needs talking through. Turnaround depends on the test: routine blood panels are quicker than genetic or DNA analysis, and we tell you what to expect at your appointment.
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