Heroin Use And Abuse: Side Effects

Heroin is an extremely addictive illegal street drug that belongs to the opioid family of substances. It is synthesized from morphine, which is an opiate chemical derived from the opium poppy.1 It generally comes in the form of a white or brown powder, but can also be purchased as “black tar heroin,” a black, sticky substance.1

Heroin can be cut, or diluted, with inert substances such as sugar or starch, but unscrupulous dealers may use harmful substances, even including poisons such as strychnine or more potent prescription opioids like fentanyl to cut heroin. The unwitting use of these adulterant substances can prove to be even more dangerous than abuse of heroin alone.

Recreational drug users inject, smoke, or snort it. Once the heroin enters the bloodstream and travels to the brain, users begin to experience its effects. Intravenously injecting it can produce effects almost instantly, whereas smoking or snorting the drug may take as long as 15 minutes to produce any effects.2 Heroin is metabolized to morphine in the brain, which then interacts with opioid receptors to diminish the perception of pain, as well as influence our natural reward systems. When certain drug thresholds are reached within the brain, various vital life functions such as breathing and heart rate will also be negatively impacted.3 The surge of opioid receptor activity that results from heroin use produces a few minutes of intense pleasure, or euphoria, followed by an hour or so of relaxation.2 Beyond the euphoric high, other commonly encountered short-term effects include nausea, vomiting, and skin itching.2 Almost half a million people aged 12 or older were current heroin users in 2014.4 In 2011, 20.6% of all emergency department visits related to illicit drug use involved the use of the drug.5 Still, while undeniably dangerous, heroin does not affect everyone in the same way. The age and weight of a user, as well as the use of other drugs, the presence of other medical conditions, tolerance, and even mood at the time of use, are all factors that can affect the severity of the short-term effects experienced. Since the physical and psychological heroin side effects may be dangerous and unpredictable, the drug is not legal for any purpose in the United States. Even the short-term effects of using it as a recreational drug can include permanent disability or death. Dependency, or addiction, is the most common of long-term heroin effects—it is often considered one of the most addictive substances that is commonly abused for its mind-altering effects.


The immediate and short-term effects of heroin use will vary by how much is taken and the method of use.6 Injecting generally produces a faster, more intense high, while snorting or smoking has a relatively delayed, less-intense onset of effects.2 Beyond the user’s subjective euphoria, heroin’s short-term side effects may include the following:6 Drowsiness Sense of heaviness in arms and legs Dry mouth Nausea Vomiting Skin flushing Intense itching Slow cardiac system function Slow breathing

Heroin’s effects that involve the cardiac and respiratory systems may be extremely serious or even fatal. They are among the reasons that heroin use can lead to medical emergencies that require immediate treatment, including overdose death. More than 10,000 people died of heroin overdose in the U.S. in 2014.7 Short-term and immediate adverse effects of heroin may require treatment with a medication called naloxone that blocks the interaction of the drug with opioid receptors.8 As an emergency antidote to an overdose, naloxone has the potential to rescue people from the brink of respiratory failure and consequently save lives.


In addition to drug dependence, long-term heroin use is associated with a number of potentially severe illnesses and addiction development. Anoxic brain damage can result from repeated use, resulting in long-lasting imbalances in brain and hormone systems.6 Injection users who share needles also run an increased risk of contracting blood-borne pathogens, such as HIV and hepatitis B and C.2 Beyond brain damage and disease contraction, the following long-term effects of heroin use are often observed:2, 3 Collapsed veins Infection of the heart lining and valves Pus-filled infections (i.e., abscesses) Liver or kidney disease Pulmonary complications Spontaneous abortion Gastrointestinal problems (e.g., chronic constipation, bowel obstruction) Infections are usually caused by sharing needles, but even users who do not inject the drug are at risk for many of the complications of long-term heroin use.