Blue Horizon Medicals Drug & alcohol testing

Carbohydrate Deficient Transferrin (CDT)

A blood test measuring Carbohydrate Deficient Transferrin (CDT), used to assess recent alcohol intake, including for DVLA evidence after a licence has been lost due to a drink driving offence.

  • Doctor reviewed
Sample
Blood
Collection
Venous draw at clinic or nurse home visit
Results in
7 days
Biomarkers
1
Doctor reviewed
Yes
Tests for
  • Carbohydrate deficient transferrin

Test specifications

Provider
Blue Horizon Medicals
Sample type
blood
Collection method
venous draw at clinic or nurse home visit
Turnaround time
7 days
Biomarkers tested
1
At-home test
No
Doctor reviewed
Yes
Gender focus
Both

What's tested

1 biomarker as listed by Blue Horizon Medicals.

Alcohol consumption

  • Carbohydrate deficient transferrin

About this test

CDT rises with sustained high alcohol intake over the 2 to 3 weeks before the sample is taken, which is why it is used to assess recent drinking, either as an initial check or to monitor a change in consumption over time. As the provider notes, the DVLA may request this result as evidence of low alcohol intake if you have lost your licence following a drink driving offence.

As a single-marker test it scores reasonably for clinical depth against the toxicology tests we track. It scores particularly well on price, well below the median for similarly sized toxicology tests we track, though collection convenience is more limited, needing a venous draw at a clinic or nurse visit rather than an at-home kit, with results back in around 7 days. The listing is clear, covering a short description, the biomarker, sample type, turnaround and collection options.

Blue Horizon Medicals has been trading since 2009, uses UKAS ISO 15189 partner labs, and has a Trustpilot score of 4.2 from 395 reviews. A doctor reviews the result before you receive it.

Who is it for?

This suits you if you want an objective marker of recent alcohol intake, whether to check your own consumption or because the DVLA has asked for evidence after a drink driving licence loss. It is not suitable as a snapshot of a single drinking episode, since it reflects sustained intake over roughly the previous 2 to 3 weeks rather than very recent or occasional drinking. We do not have peer tests logged in this comparison group, so we cannot compare it directly with other providers' CDT tests.

How it works

A healthcare professional takes a venous blood sample at a clinic or during a home nurse visit; there is no at-home collection option for this test. The lab measures your CDT level, and a doctor reviews the result before it is released to you, typically within around 7 days.

Pros & cons

Pros

  • Well below the median price for similarly sized toxicology tests we track.
  • Accepted by the DVLA as evidence of alcohol intake in licence cases.
  • Home nurse visit available if a clinic visit is not convenient.
  • Doctor-reviewed result included as standard.

Cons

  • No at-home collection option, only a venous draw.
  • Turnaround of around 7 days.
  • Reflects sustained intake over 2 to 3 weeks, not a single drinking episode.

Our editorial score

Compare Health Test Score CDT alcohol test, priced below the toxicology median
Editorial confidence: 10.0/10

Recent alcohol intake, including for DVLA purposes after a drink driving licence loss, is what Carbohydrate Deficient Transferrin (CDT) assesses. At £101.25 this test is priced well below the median for similarly sized toxicology tests we track, though it needs a venous draw at a clinic or nurse visit, with results in around 7 days.

Score breakdown

  • Clarity and documentation 8.0/10

    The listing publishes a short description, the full biomarker list, a stated turnaround, clear collection options, the sample type; it does not state what the report looks like.

  • Clinical depth 7.2/10

    1 biomarkers, placing it in the 44th percentile of toxicology tests we track.

  • Collection convenience 8.0/10

    A blood sample taken at home by a visiting nurse or phlebotomist; with a venous or clinic option as well; a home nurse visit is offered; results in around 7 days, slower than similar tests.

  • Results and follow-up 7.0/10

    Results are reviewed by a doctor; the provider does not describe the report format.

  • Trust signals 7.5/10

    Trustpilot 4.2 from 395 reviews; accredited lab (UKAS ISO 15189 partner labs); trading 17+ years.

  • Value for money 8.9/10

    £101.25 against a median of £195.00 for the 8 similarly sized toxicology tests we track (-48%).

Calculated 13 September 2026 from the facts we hold about this test and provider, using our published scoring formula. Scores are not hand-edited.

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