ALEX3 Allergy Test
£413.75
- 290+ allergens from one blood sample
- Written report in about five working days
- No antihistamine pause
ALEX3 · 290+ ALLERGENS · HARLEY STREET
ALEX Allergy Test London
The ALEX3 allergy test at 117a Harley Street, London costs £413.75 and screens 290+ allergens from one blood sample. One blood sample screens foods, pollens, animal dander, moulds, house dust mites and insect venoms, with a written report in about five working days.
Results5 working days
Time20-30m
Price£413.75
AvailabilityBook Online
Est. 1984
Trusted clinical caresince 1984
UKAS-accredited labsGP & consultant pathways
As Featured In
ALEX allergy test in London
The ALEX3 allergy test at Medical Express Clinic costs £413.75 and screens sensitivity to 290+ allergens from one blood sample.
ALEX3 covers whole extracts and molecular allergen components across foods (nuts, shellfish, milk, egg, wheat, fruit), tree and grass pollens, cat and dog dander, moulds, house dust mites and insect venoms.
Results typically arrive within five working days with a comprehensive written report.
ALEX3 is not affected by antihistamines, so it is the better choice when you cannot pause your tablets or when your symptoms overlap.
You can book ALEX3 directly online or by calling 0207 499 1991, and the blood sample is taken at 117a Harley Street, London.
How much does the ALEX allergy test cost in London?
The ALEX3 allergy test costs £413.75 at Medical Express Clinic, with sample collection charged at £50. A consultation with Dr Scott Pereira to review the result costs £250.
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Allergy Consultation
£250
- Dr Scott Pereira, Consultant Immunologist
- Results read against your symptoms
- Tuesdays, 14:00 to 17:30
What the ALEX3 allergy test covers
From one blood sample, ALEX3 screens sensitivity to 290+ allergens across whole extracts and molecular allergen components. It covers foods (nuts, shellfish, milk, egg, wheat, fruit), tree and grass pollens, cat and dog dander, moulds, house dust mites and insect venoms.
It is particularly helpful when symptoms overlap or when you cannot stop taking antihistamines. Results typically arrive within five working days with a comprehensive written report. ALEX3 is not a same-day test.
Understanding an ALEX3 result
A raised skin prick or blood IgE result shows sensitisation rather than a confirmed clinical allergy. Dr Pereira interprets every positive finding against your actual symptoms and reaction history before recommending avoidance or treatment.
If you want the result reviewed, bring it to a £250 consultation. Dr Pereira interprets it against your symptoms and advises whether any further testing, medication or desensitisation is appropriate.
ALEX3, skin prick test or a targeted panel?
Choose ALEX3 when you have several possible triggers or cannot stop antihistamines. Choose a skin prick allergy test (£450, including the consultation) when you can pause antihistamines for 72 hours and want results in 15 to 20 minutes.
When your history already points to one group of triggers, a targeted IgE blood panel taken during a consultation is often more focused than a 290-allergen screen. The panels and their prices are on our private allergy testing in London page.
Book an ALEX allergy test
Book ALEX3 (£413.75) online or call 0207 499 1991. ALEX3 blood draws are booked through our phlebotomy team at 117a Harley Street, London.
Clinical lead
Dr Scott Pereira MA, MB, B Chir, PhD, FRCPath
Immunology & Allergy • GMC 1524080
“Dr Pereira is a consultant immunologist with over 30 years of experience in complex allergy diagnosis, allergic rhinitis, urticaria and allergen desensitisation (immunotherapy).”
Verified Patient Feedback
What our patients say
“Results faster than expected at a walk-in clinic”
“I recently had a blood test for rabbit allergies at Medical Express Clinic, and I'm extremely pleased with the service. Not only did I receive my results faster than expected, but the receptionist was fabulous, she answered all my questions and accommodated all my requests. It's the only walk-in clinic I found in central London with reasonable prices. Highly recommend this clinic!”
Alessandro P.Walk-In Allergy & Blood Test
Trustpilot Review“Heard, understood and reassured”
“The clinic is warm and welcoming. In my experience, every time I was there, I found myself heard and understood. My health issues have been tackled in the best of ways. Miss Arjeta is absolutely a master of blood tests, you will not feel anything. Dr Bakhtiar is knowledgeable and calm, I always feel reassured after speaking to him. I genuinely recommend this clinic.”
Verified Patient · Jan 2026Private GP & Blood Testing
Google Review“Best medical practice I've been to globally”
“By far the best medical service I have received. Exceptionally fast, extremely knowledgeable doctor and the best medical practice I’ve been to globally.”
Dom R. · Sept 2026Private GP & Health Screening
Google ReviewFAQs
ALEX allergy test FAQs
How much does the ALEX allergy test cost in the UK?
The ALEX3 allergy test costs £413.75 at Medical Express Clinic in London. Sample collection is £50.
How many allergens does ALEX3 test for?
ALEX3 screens sensitivity to 290+ allergens from one blood sample, across whole extracts and molecular allergen components.
How long do ALEX3 results take?
ALEX3 blood results typically take five working days and come with a comprehensive written report. ALEX3 is not a same-day test.
Do I need to stop antihistamines before an ALEX3 test?
ALEX3 and targeted blood panels are not affected by antihistamines, so a blood test is the better choice if you cannot pause your tablets.
Do I need a consultation before booking ALEX3?
You can book the ALEX3 290+ allergen blood test directly, without a consultation first. If you want Dr Pereira to review your symptoms first and choose the right test on the day, book the £250 consultation.
