Rehab 4 Addiction

Speedballing – Cocaine & Heroin

The mixing of the illicit drugs Heroin and cocaine is typically called ‘speedballing’.

This involved the injection of both substances simultaneously into the bloodstream. They can be injected together or snorted together.

Users claim to duo-dose to experience an extremely intense high, more so than what you would get from an isolated drug use.1

Heroin is an opioid (a depressant), and cocaine is a stimulant.

The concurrent use of a depressant and a stimulant combination can also be ‘piggy-backed’.

This includes injecting immediately before or after heroin. The drugs can be ‘backloaded’ into the same syringe.

Consuming cocaine and heroin together can create a push-pull reaction on the body and brain.

Users experience an intense rush, whilst maintaining hopes of a reduction in side effects. Heroin makes users drowsy, slowing down their breathing.

This makes it difficult to stay awake during the high, but cocaine fixes this with bursts of energy.

This isn’t the only opposite of the drugs, cocaine causes users to be anxious and paranoid, but heroin emulates a feeling of serenity and calmness.

The common misconception here is that the drugs will cancel each other out, like the rapid heart rate from cocaine and the calming effect of heroin.

Combining these two substances and speedballing is more dangerous than using them individually; their negative effects and the comedown is more amplified when they are united.

The Effects of Speedballing

Mixing two drugs such as heroin and cocaine can increase the risk of overdose, conflicting permanent damage.

You are forcing the body to process two types of drugs simultaneously, an immense amount of pressure and strain.

Taking a depressant and a stimulant together as a cocktail has very high risks, with unpredictable side effects.

Cocaine demands more oxygen from you, whilst heroin slows down your breathing. This strain causes confusion in the overactive heart and lungs.

The lack of oxygen in your body makes it difficult to balance out the effects of the drugs, leading to a longer period of stress.

Cocaine wears off faster than heroin, meaning users are likely to use again or overdose thinking they didn’t inject enough.

The side effects commonly associated with Cocaine:

  • Anxiety
  • Hypersensitivity
  • high blood pressure
  • irregular or rapid heartbeat

Opioids such as Heroin are associated with:

  • drowsiness
  • slowed breathing
  • flushing of the skin
  • dry mouth
  • clouded mental function
  • nausea and vomiting

Effects of Speedballing:

  • Confusion and incoherence
  • Drowsiness
  • Extreme paranoia
  • Lack of sleep
  • Mental impairment
  • Involuntary movements (uncontrolled motor skills)
  • Stupor
  • Lack of awareness


Both opioids and stimulants are highly addictive and destructive to both your body and mental health.

Once you develop a tolerance to the drugs, you are more likely to use both at the same time to achieve a better and bigger high.

Sharing needles, syringes and other injecting equipment puts agents at risk of viral hepatitis, HIV and other deadly infections.

These diseases are transferred through bodily fluids such as blood.3 HIV can survive in a needle for up to 42 days, depending on factors such as temperature.

Speedballers exhibit more severe psychopathology compared to single drug users. This means you are more likely to fail substance use treatment.

There are long term side effects of combining drugs and speedballing. The body, including the lungs, liver and heart appear to be the worse affected.

There are equally bad effects on the mind, with common effects being manic episodes, depression, and paranoia.

The risk of death is very high:

  • Stroke and heart attack
  • Aneurysm
  • Respiratory failure
  • Organ failure

Mixing Drugs

The differences in cocaine and heroin highlight the risk of respiratory failure.

Once the effects of cocaine wear off, the impairing effects heroin has on the lungs is in full swing.

The poly-use of drugs is a key facilitator in the world of overdosing.

A lack of awareness of how much is still in your body, may lead you to ingest more.4

Using cocaine and heroin at once uses different mechanisms in the body, overlapping in the brain. For example, the more heroin in the body, the less cocaine required to lead to an overdose.

Whilst it seems common thought that mixing would counterbalance effects, this is not the case.


  • You are forcing the body to process multiple substances
  • Whilst cocaine causes the body to use oxygen rapidly, heroin slows the breathing rate, meaning you are getting an insufficient amount of oxygen.

How to help:

  • If you use, use one drug at a time and be careful of the dose
  • Reduce the amount you take or use drugs
  • Avoid mixing substances like alcohol with drugs

Tolerance and Quality

Concerning processing drugs, the amount you are able to process is labelled tolerance.

Low tolerance means you only have to take a small amount of the drug to achieve its desired effects.

High tolerance means your body has learned how to tolerate a lot of a single substance.

Although tolerance develops over time, its dependant on factors such as weight, age and immune system just to name a few.5

The fact tolerance is different for everyone means that overdosing becomes easy. You never really know how much you can take before it’s too late.

Tolerance can decrease when you take a prolonged absence from using, tricking you into thinking you require more than you actually do.

Quality refers to how pure the drug you’re using. This is the issue with street drugs, as they’re usually cut with lethal substances to make it stretch further.

This means that the shot you took yesterday was really weak, but the shot tomorrow might be so strong it kills you.

This also means you should also be cautious about all drugs.

Knowing and understanding quality and tolerance is always a cloudy area, so it’s best to assume your tolerance is low and the purity of the drug is high.

Some Tips for You

  • If you use constantly, develop an overdose plan with someone, possible including leaving a door unlocked.
  • Calling someone you trust to tell them your speedballing is the safest idea.
  • Try to remain sober and eat regularly to decrease your body’s chances of shutting down – help it any way you can.
  • Try to NEVER use on your own
  • If you end up in the hospital, be totally honest. Doctors are there to help you, not judge you.

The biggest piece of advice is to abstain from drugs altogether – their negative effect outweighs the high itself.

If you feel like you are at risk of an overdose, or simply think you require help for an addiction, don’t be afraid to get in touch.

Our treatment programmes are state of the art, with both private and council funding. Whatever option Is best for you, we have it covered.


  2. Negus SS, Gatch MB, Mello NK. Discriminative stimulus effects of a cocaine/heroin “speedball” combination in rhesus monkeys. J Pharmacol Exp Ther. 1998 Jun;285(3):1123-36. PMID: 9618415.
  5. Warner-Smith M, Darke S, Day C. Morbidity associated with non-fatal heroin overdose. Addiction. 2002 Aug; 97(8):963-7.



Boris is our editor-in-chief at Rehab 4 Addiction. Boris is an addiction expert with more than 20 years in the field.  His expertise covers a broad of topics relating to addiction, rehab and recovery. Boris is an addiction therapist and assists in the alcohol detox and rehab process. Boris has been featured on a variety of websites, including the BBC, Verywell Mind and Healthline.