1,25-dihydroxyvitamin D (calcitriol)
This test measures 1,25-dihydroxyvitamin D, the biologically active form of vitamin D. It is used to investigate calcium imbalance, kidney disease and...
The urine porphyrins screen helps detect abnormalities in heme metabolism. It supports investigation of porphyria and unexplained neurological or abdominal symptoms.
Turnaround time
3 weeks
Biomarkers count
1
Professional phlebotomist comes to you
+ £{{ home_visit_fee }}
Visit our clinic for your test
{{ clinic_visit_fee > 0 ? '+ £' + clinic_visit_fee : 'Free' }}
Home visits require at least 24 hours notice.
{{ clinic.full_address }}
{{ selectedClinic.full_address }}
Available time slots: {{ timeSlots.length}}
{{ addon.excerpt }}
SelectedThe Porphyrins Screen (Urine) measures porphyrins and their precursors excreted in urine. Porphyrins are compounds involved in the production of heme, a critical component of haemoglobin and other essential proteins.
Abnormal accumulation of porphyrins can indicate porphyria, a group of rare metabolic disorders affecting heme synthesis. Urine testing is particularly useful because excess porphyrins are often excreted during active or symptomatic phases.
This screen is commonly used as a first-line investigation when porphyria is suspected based on symptoms or family history.
Porphyria can cause vague, episodic, and often severe symptoms that are difficult to diagnose without targeted testing. The urine porphyrins screen helps identify biochemical abnormalities that explain these symptoms.
Testing is especially important when symptoms are recurrent, unexplained, or triggered by medications, hormones, fasting, or illness.
You may benefit from this test if you experience:
Severe or recurrent abdominal pain
Unexplained neurological symptoms
Peripheral nerve pain or weakness
Sensitivity to sunlight with skin blistering
Dark or reddish urine
Episodes triggered by stress or medication
Family history of porphyria
Unexplained psychiatric or cognitive symptoms
Supports detection of porphyria
Identifies abnormal porphyrin excretion patterns.
Assists investigation of unexplained symptoms
Useful when standard tests fail to identify a cause.
Non-invasive diagnostic approach
Requires only a urine sample.
Detects active metabolic disturbance
Particularly helpful during symptomatic episodes.
Guides further specialist testing
Helps determine need for genetic or plasma studies.
Supports family risk assessment
Useful when porphyria is suspected genetically.
Helps avoid trigger exposure
Early detection supports safer medication and lifestyle choices.
Improves diagnostic clarity
Reduces delays in diagnosing rare metabolic disorders.
Choose your nearest UK clinic
Attend your appointment
Provide a urine sample following instructions
Sample is sent to the laboratory for analysis
A clinician or phlebotomist visits your home or hotel
Urine sample collected at your location
No clinic visit or travel required
Both services are available UK-wide.
Normal results indicate no significant excess porphyrin excretion. This makes active porphyria unlikely at the time of testing.
Symptoms may still require further investigation if they persist or fluctuate.
UK reference interpretation:
Normal: Within laboratory reference ranges
Raised porphyrins suggest disruption in heme synthesis and may indicate a form of porphyria or secondary porphyrin elevation due to liver disease, alcohol use, or medication effects.
Further testing is often required to identify the specific type.
UK reference interpretation:
Elevated: Above reference ranges
Significantly raised porphyrins strongly suggest active porphyria, particularly if symptoms are present. This warrants specialist referral and confirmatory testing.
UK reference interpretation:
Markedly raised: Significantly above reference ranges
Simple steps to get your results
Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
Take control of your health with London Blood Tests
WhatsApp UsFollow these guidelines for accurate results
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.
Discover more options in this category:
This test measures 1,25-dihydroxyvitamin D, the biologically active form of vitamin D. It is used to investigate calcium imbalance, kidney disease and...
This test measures 17-hydroxyprogesterone, a hormone involved in cortisol production. It is used to assess adrenal function and diagnose congenital ad...
The 5-HIAA (5-Hydroxyindoleacetic Acid) blood test measures the amount of 5-HIAA, a breakdown product of serotonin, in the bloodstream. Elevated level...
This test measures 6-thioguanine nucleotide levels to monitor thiopurine medications. It helps optimise treatment effectiveness while reducing toxicit...
This PCR screen detects seven common sexually transmitted infections with high accuracy. It identifies active infections even when symptoms are mild o...