Mind-altering substances can have an intensifying or disinhibiting effect during sex. They can have different functions. For example, they can increase the libido or relax the muscles for anal intercourse. At the same time, the inhibition threshold to engage in unprotected sexual intercourse and thus expose oneself to the risk of contracting STIs is lowered. Sex in connection with substance use carries risks: especially with high dosages, strongly sedating substances and/or mixed use. It is also possible to get involved in things you don't really want while intoxicated, and to forget or be willing to deliberately disregard the safer sex rules.

Safer Sex

"Safer sex" means not only pregnancy prevention, but also protection against sexually transmitted diseases such as HIV (an HIV infection is still not curable!), hepatitis C, syphilis, gonococci and chlamydia. Even when under the influence of substances, don't forget condoms! Be careful during oral sex, do not put sperm or (menstrual) blood in your mouth. With sex partners whose state of health you do not know, always blow with a rubber!

So that the "sex trip" does not become a "bad trip

Only use psychoactive substances for sex with mutual consent.
Discuss before sex which substance and which dose you want to use.
Clarify with your partner in advance which sex practices are OK and which are taboo.
Agree on a stop sign to let your partner know when they are going too far.
Never use in such a way that you are unable to resist or that you no longer notice your partner's defensive signals.
Condoms and lubricant should always be used together and within easy reach. The longer sex lasts, the more important it is to change the condom and use lubricant (especially for anal sex).
Ecstasy, speed, LSD and cocaine dry out the mucous membranes (risk of the condom tearing and increased risk of HIV infection).

If you've had unprotected sex with strangers...

...you could have contracted HIV or another sexually transmitted infection (STI):
Post-exposure prophylaxis (PEP) can reduce the risk of infection with HIV. You have a maximum of 72 hours to seek counselling at the AIDS centre or the nearest hospital. If it is indicated, you will be given PEP; you will then have to take medication for a month. This does not completely eliminate the risk of infection, but it greatly reduces it. Taking these drugs can be associated with considerable side effects. 

There is also the option of taking medication before planned sex with an HIV-positive person. Pre-exposure prophylaxis (PrEP) reduces the risk of HIV infection, but does not provide protection against hepatitis C and other sexually transmitted diseases.

More information on PEP and PrEP

More information about STI

...you could become pregnant unintentionally:
If you are not taking any other contraceptives, you can get the morning-after pill from any pharmacy. It is also available for women under the age of 16 (from family doctors, gynaecologists, family planning centres or hospital emergency wards). Taking this medicine can be associated with considerable side effects.

Keep an eye on your body after you have had unprotected sex. If you notice any changes (discharge from the vagina or penis, skin changes, etc.), contact a doctor immediately.

Who covers the costs of treatment for sexually transmitted infections?

Medical treatments are covered by the basic health insurance. You have to pay the deductible rate and the excess yourself as usual.

Professionals are bound by professional secrecy and may not pass on any data to third parties without your express consent.

If someone sexually harasses you at a party....

... and doesn't stop despite a clear no from you, inform the security or bar staff.
Watch out if someone tries to make you compliant with drinks or substances offered to you and always keep an eye on your drink.
If you have been the victim of sexual violence, go to hospital immediately for an examination and contact a victim counselling centre (there is one in every large city for free help and support).
Get advice at the hospital or from a counselling centre on how to proceed and the consequences of reporting.

You can find victim counselling centres here.

Substances with a high risk potential in connection with sexual behaviour:

Think carefully about how high the dose should be for which substance. This depends on your body weight, among other things. Find out about each substance individually.

Increased risk behaviour due to disinhibition and/or overestimation of oneself. Alcohol consumption is one of the most frequent reasons for unprotected sexual intercourse! Alcohol is also abused to make others sexually compliant.

You can find more information about alcohol here.

Increased risk behaviour due to disinhibiting effect and increased sexual desire. GHB and GBL are also abused to make others sexually compliant ("knockout drops").

You can find more information about GHB/GBL here.

Increased risk behaviour due to pain-inhibiting, sexually stimulating, aphrodisiac and euphoric effects. 

You can find more information about poppers here.

Increased risk behaviour due to narcotic effect and loss of reality.

You can find more information about ketamine here.

Methamphetamine (Crystal):
Risky behaviour due to stimulating, pain-inhibiting, aphrodisiac effect as well as self-overestimation.

More information on methamphetamine can be found here.

Increased risk behaviour through disinhibition and overestimation of oneself. Increases blood flow and thus arousal in women (in men, however, it can cause erectile dysfunction).

You can find more information on cocaine here.

Other substances not mentioned here can also promote risky behaviour.