In short
A proof of abstinence (Abstinenznachweis) for the MPU shows over 6 or 12 months that you have not consumed alcohol or drugs. It only counts if it meets the CTU criteria: an accredited laboratory, unannounced tests and complete documentation. Urine screenings, hair analyses and the blood marker PEth are possible.
When do you need a proof of abstinence for the MPU?
You usually need a proof of abstinence (Abstinenznachweis) if your MPU (medical-psychological assessment, Medizinisch-Psychologische Untersuchung) was ordered because of alcohol or drugs. The proof must cover the period of abstinence before the assessment. For an MPU because of points, it is usually not necessary.
How long you have to provide proof depends on the severity and history of your case. 6 or 12 months are common, and 12 months are frequently required. In cases of dependence, at least 12 months are usually necessary, and 1 year for cannabis dependence as well. In milder alcohol cases without a finding of dependence, stable controlled drinking may also be an option instead of abstinence. You can find details on the reasons under MPU because of alcohol and MPU because of drugs.
What do the CTU criteria mean?
The CTU criteria set out the formal requirements a proof of abstinence must meet in order to be recognised for the MPU. CTU stands for chemical-toxicological testing (Chemisch-Toxikologische Untersuchung); the criteria are part of the assessment criteria (Beurteilungskriterien) and the assessment guidelines (Begutachtungsleitlinien). A proof that does not meet them is practically worthless for the MPU.
The most important requirements are:
- Accredited laboratory according to DIN EN ISO/IEC 17025 in the field of forensic toxicology
- Unannounced appointments with short-notice summons, usually within about 24 hours of the request
- Identity check and, for urine, a sample given under observation
- Complete documentation of the sample chain from the collection point to the laboratory (chain of custody)
- Continuous duration – one missed or manipulated appointment can invalidate the entire programme
Before registering, ask whether the assessment centre (Begutachtungsstelle für Fahreignung, BfF) recognises the programme.
Which methods are there: urine, hair or PEth?
There are three common methods for proof of abstinence: urine screening, hair analysis and the blood marker PEth. Which one suits you depends on the substance, your case and partly also on your hair.
| Method | Covers | Typical frequency |
|---|---|---|
| Urine screening | Alcohol (EtG) and drugs | 6 months = 4 tests, 12 months = 6 tests |
| Hair analysis | Drugs and alcohol (EtG) | For alcohol max. 3 cm of hair = about 3 months per analysis, so several analyses for 12 months |
| PEth (blood) | Alcohol (marker of amount consumed) | Supplementary or alternative, increasingly used |
Urine screening is flexible but requires you to be reachable at short notice at any time. Hair analysis looks back over a longer period but only works with untreated hair. PEth has been recognised for the MPU since the 4th edition of the assessment criteria (2022) and is increasingly becoming the standard.
As a guideline (as of 2026), costs are around €60–120 per urine sample and €120–200 per hair sample. In total, an abstinence programme costs around €200–900, depending on duration and method. The page MPU costs gives an overall overview.
What do the laboratory markers show?
Depending on the method, the laboratory markers show for different lengths of time whether alcohol has been consumed. That is why the test appointments are at such short notice: the marker in urine can only be detected for a few days.
| Marker | Sample | Detection window | Reference value |
|---|---|---|---|
| EtG (ethyl glucuronide) | Urine | about 24–80 hours | Direct alcohol marker |
| EtG (ethyl glucuronide) | Hair | retrospectively about 3 months (max. 3 cm per analysis) | Direct alcohol marker |
| PEth (phosphatidylethanol) | Blood | consumption over roughly the last 2–4 weeks | < 20 ng/ml = abstinence |
| PEth (phosphatidylethanol) | Blood | consumption over roughly the last 2–4 weeks | 20–200 ng/ml = relevant consumption |
| PEth (phosphatidylethanol) | Blood | consumption over roughly the last 2–4 weeks | > 200 ng/ml = excessive consumption |
Liver values such as GGT, GOT/GPT, MCV and CDT only indicate alcohol consumption indirectly. Today they hardly play a role in the actual proof of abstinence, but they can show good values as a supplement. For drugs, urine is screened for classes of substances and/or a hair analysis is carried out.
What do you need to watch out for during abstinence?
During abstinence, you mainly need to pay attention to the zero-alcohol rule (in German "0,0-Regel"), to being reachable and to your hair. Even small mistakes can cost you months of proof time.
Do not dye your hair
Dyed, bleached or tinted hair makes the EtG hair analysis unusable. If you want or need to treat your hair, switch to urine screening or PEth.
The zero-alcohol rule
Even a single "slip" can invalidate the programme. EtG can also be triggered by foods containing alcohol or by mouthwash. If in doubt, consistently avoid such products.
What happens in the event of a relapse
A positive result or a missed appointment usually invalidates the current programme, and the abstinence clock starts again. A relapse is not the definitive end, but it does shift your schedule. Do not conceal it: a concealed relapse that comes to light later will completely destroy your credibility. It is better to put it into context honestly, understand the cause and make a clean new start.
What are the absolute no-gos for proof of abstinence?
The biggest no-go for proof of abstinence is bought or forged proof. "Ready-made" proofs, clean results for money or backdated programmes constitute forgery of documents (Urkundenfälschung) – you should definitely stay away from them.
Note: A proof without an accredited laboratory, without unannounced appointments or with gaps is generally not recognised for the MPU.
It is also risky to start abstinence "on a trial basis". Only start the programme when you really intend to see it through, otherwise you will lose time and money.
How do you start your proof of abstinence correctly?
You start your proof of abstinence correctly by first clarifying the requirements and then registering immediately with a recognised programme. The most common and most expensive mistake is a programme started too late or incorrectly.
- Apply for file inspection (Akteneinsicht): Are 6 or 12 months required, and for which substances?
- Choose a recognised laboratory: Only accredited according to DIN EN ISO/IEC 17025 and recognised by the assessment centre – ask beforehand.
- Register immediately: The proof period is the bottleneck of your entire planning.
- Decide on the method: Urine, hair or PEth, suited to the substance and your daily life.
- See it through without gaps: Every appointment counts; always carry your ID for urine samples.
- Collect your documents: Keep all results in the original and bring them to the MPU.
How the proofs are used on the day of the assessment is explained in How the MPU works.
What happens next?
Use file inspection to clarify which period and which substances apply to you, and then register with a recognised programme without delay. Alongside abstinence, professional preparation is worthwhile so that you can explain your change credibly in the interview. Through MPU Plus you can find suitable counselling.
Frequently asked questions
How often are you tested with a urine proof of abstinence?
A 6-month programme typically involves 4 tests, a 12-month programme 6 tests. The appointments are unannounced, and you usually have to attend within about 24 hours to give a sample. The sample is given under observation and with an identity check.
Which PEth value counts as abstinent?
According to the assessment criteria, a PEth value below 20 ng/ml counts as abstinence. Values from 20 to 200 ng/ml indicate relevant consumption, values above 200 ng/ml excessive consumption. PEth reflects alcohol consumption over roughly the last 2 to 4 weeks.
Can I dye my hair if I am having a hair analysis?
No, dyed, bleached or tinted hair makes the EtG hair analysis unusable. If you do not want to give up hair treatments, choose urine screenings or PEth instead. It is best to clarify this before starting the programme.
Can mouthwash trigger a positive EtG result?
Yes, EtG can also be triggered by mouthwashes or foods containing alcohol. Because even one positive result can invalidate the programme, you should avoid such products if in doubt. Consistently follow the zero-alcohol rule during abstinence.
How much does a proof of abstinence for the MPU cost?
As a guideline (as of 2026), an abstinence programme costs around €200 to €900 in total. A urine sample costs around €60 to €120, a hair sample around €120 to €200. The total depends on duration and method.