MPU after combined use: what applies to alcohol and cannabis together?

What legally counts as combined use?

In road traffic, combined use means that you drive under the influence of cannabis and alcohol is also involved. § 24a Abs. 2a StVG expressly covers anyone who drives with 3.5 ng/ml THC or more in their blood serum and drinks alcohol while doing so or starts the drive under the effect of an alcoholic drink.

There is no separate blood alcohol limit for this. Unlike with alcohol alone (administrative offence from 0.5 ‰), the effect of an alcoholic drink in combination with the THC value is enough. The fine here can be up to €5,000 instead of up to €3,000 for alcohol or cannabis alone.

With signs of impairment or an accident, the administrative offence can become a criminal offence. You then face withdrawal of your driving licence and a ban period (Sperrfrist). The guide MPU after an accident under alcohol or drugs explains the effects.

Why can the very first drive lead to an MPU?

The first drive can lead to an MPU because combined use counts as an additional fact (Zusatztatsache). Normally, with cannabis, authorities only order an MPU for repeated offences, in practice from the second drive. § 13a FeV (Driving Licence Regulation, Fahrerlaubnis-Verordnung) does not give a fixed number for this.

Additional facts such as combined use, very high values (acutely above 11 ng/ml THC or THC-COOH above 150 ng/ml) or signs of dependence change this. The authority can then have doubts about your fitness clarified after the first incident. The combination can be an indication that control over your use is no longer reliable. The page MPU because of cannabis gives an overview of the cannabis rules.

How does the MPU differ with combined use?

The MPU for combined use differs above all through a combined question. In it, the authority can have both your drinking behaviour and your cannabis use clarified. Exactly which questions are asked is stated in your order.

Combinations such as alcohol and drugs tighten the requirements. Assessors tend to assign such cases to an advanced hypothesis. With drugs, polyvalent use, meaning the use of several substances, belongs to hypothesis D2, which usually requires stable abstinence over 12 months. With cannabis dependence, fitness is only restored after 1 year of proven abstinence.

The costs also rise. For a combined question, the fee for the expert report (Gutachten) is about €650–900 instead of €550–750 for a single reason (guide values 2026). More on the classification in MPU because of drugs.

What proof do you need with combined use?

With combined use, you usually need proof that covers both substances if the question includes both. You clarify which substances and which period are required through file inspection (Akteneinsicht) and with the assessment centre (Begutachtungsstelle für Fahreignung).

One programme can cover both substances at the same time if this is agreed accordingly. What matters is a laboratory accredited to DIN EN ISO/IEC 17025, unannounced appointments and complete documentation. Dyed or bleached hair makes the EtG hair analysis unusable. You will find all the rules under Proof of abstinence.

Note: Whether abstinence or controlled drinking is an option for alcohol depends on the hypothesis that results from your file. Do not rely on your own assumptions; clarify the way forward with a professional in advance.

What does the assessor look for in the interview?

In the interview, the assessor mainly looks at whether you have understood what function the combination had for you. Combined use raises the question of whether the effect was meant to be deliberately intensified or whether one substance lowered the threshold for the other.

Typical questions are:

• How often did you use alcohol and cannabis together, and since when?
• In which situations did this happen, and what did you want to achieve with it?
• Why did you get behind the wheel anyway?
• What have you changed since then in how you deal with both substances?
• How do you deal today with situations in which both are offered?

The assessor checks the consistency between the file, the questionnaire, the lab values and your account. If you only work through one substance and play down the other, you will seem contradictory. Tell your story honestly and in your own words. You will find typical interview questions in the guide Questions in the psychological interview.

Which mistakes should you avoid?

The most common mistakes with combined use come from playing things down and from false assumptions about legalisation. Otherwise these points will cost you time and money:

• Taking only one substance seriously: the legalisation of cannabis does not change the fact that the combination at the wheel is prohibited.
• Starting abstinence too late: the proof period of 6 or 12 months is usually the bottleneck of the whole timetable.
• Underestimating slip-ups: a positive result or a missed appointment can invalidate the programme.
• Downplaying quantities: contradictions with the measured values are noticed immediately.
• Learning model answers: assessors recognise rehearsed sentences.

What you can do now

1. Apply for file inspection and check whether the order covers alcohol, cannabis or both.
2. Clarify with the assessment centre which substances and which period need to be proven.
3. Start an abstinence programme immediately at an accredited laboratory that covers both substances.
4. Work through the role the combination played for you, instead of only looking at the drive.
5. Get professional support for working through it: find suitable preparation.