Last checked for clinical accuracy on 3 March 2025. This article is general information and is not a substitute for advice about your own situation.
Synthetic drug side effects vary widely with the substance. Fentanyl brings pain relief, relaxation and euphoria, but also drowsiness, nausea and respiratory depression. Synthetic cannabinoids can raise heart rate and blood pressure and cause agitation, paranoia, numbness, seizures or heart attacks. Synthetic cathinones, sold as bath salts, produce energy, euphoria and sometimes delirium. Molly causes alertness, dehydration, chills and sleep problems. Across all of them, the shared risk is dependence.
A note before you read on
This article is general information, not medical advice about your own situation. If you are worried about your own or someone else's substance use, speak to your GP. In an emergency call 999 in the UK, or 112 anywhere in Europe.
Many drugs can be found in nature. For example, opium is extracted from poppy, cocaine is extracted from the coca plant, and marijuana is grown. But some drugs are made in a lab and distributed, often illicitly, for recreational use. These drugs can have different effects based on what they are. Synthetic drug side effects can vary greatly. However, one common effect that they can have is a higher tendency for addiction for the people who use them. Regardless of what the drug is, addiction is still dangerous and is something that needs to be overcome. At Sierra Recovery, we help people recover from substance use disorders in our rustic treatment facility in the mountains of Malaga.
Types of Synthetic Drugs
Synthetic drugs can be difficult to enforce. Laws can be amended to ban ones on the market, but a single change to a drug's formula can technically make it so that the amended laws no longer apply. Synthetic or designer drugs are not all the same. Some are stimulants, some are depressants, and so on. Some of the common synthetic drugs include:
Fentanyl
While opioids are extracted from the poppy plant, fentanyl is a synthetic opioid that is 50 times stronger than heroin and 100 times stronger than morphine, making it an incredibly powerful pain reliever and also incredibly addictive. England has seen a rise in fentanyl use enough that it has become a risk to public health.
Cannabinoids
Synthetic cannabinoids are lab-made substances that are created to resemble and mimic the effects of the cannabis plant on a chemical level. Despite this, their effects can differ from those of marijuana. Cannabinoids can have some medical applications, but many are sold and used illicitly for recreational purposes.
Bath Salts
Bath salts are synthetic versions of cathinone, naturally found in the khat plant. They are psychoactive drugs that are designed to evade detection from law enforcement. Bath salts can be potent stimulants similar to methamphetamine and MDMA, and they can also have mind-altering effects.
Molly
Molly is a supposedly purer version of ecstasy. Molly is a stimulant with mind-altering properties and can often be 'cut' with other chemicals.
Side Effects of Synthetic Drug Use
People who use synthetic drugs can be affected by a variety of side effects depending on the substance they've taken. The effects of synthetic drug abuse can be unpredictable, but some of the common effects include:
Effects of Fentanyl
Fentanyl can have numerous immediate effects. As an opioid, one of its most prominent effects is pain management. People who use fentanyl can also become relaxed and feel a sense of euphoria. However, not all short-term effects are positive. Some people can become drowsy and nauseous, and they may even suffer respiratory depression.
Effects of Cannabinoids
Synthetic cannabinoids, which are sometimes referred to as spice or K2, can have several short-term effects. These can include increased heart rate and blood pressure. Some users of synthetic marijuana may also become agitated, anxious, or paranoid. Others may feel numbness or tingling. Other effects include restricted blood flow to the heart, seizures, and heart attacks.
Effects of Synthetic Cathinones
Synthetic cathinones are stimulants. As such, people who use them may experience a burst of energy and alertness. Some users may also have an out-of-body experience; they may feel a sense of euphoria, and some may become delirious.
Effects of Molly
Molly can have several immediate effects. They can include increased alertness and motor activity. Some people can feel more empathetic and may become less inhibited. Dehydration is a common effect of molly, and some users may get chills, blurred vision, and sleep problems.
Long-term Effects of Synthetic Drug Use
Long-term synthetic drug addiction can have many adverse effects. Like many drugs, one of the most dangerous effects is dependence. When a person becomes dependent, they may suffer withdrawal symptoms if they ever cease their substance abuse. This dependence fosters regular use, which can eventually lead to tolerance. Tolerance can be profoundly dangerous because it can dull the effects of a drug. Because of this, many can increase their drug intake. Psychologically, people struggle with maintaining relationships and health when they become dependent as the drug becomes a central focus in their lives. Increasing drug intake will increase a person's risk of overdose. Overdoses on drugs are often fatal if not given immediate medical treatment. Many synthetic drugs can cause long-term cognitive and emotional difficulties, and users may find themselves having trouble regulating their emotions.
Do you think you or someone you love has a problem with synthetic drugs?
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Treatment for Synthetic Drug Misuse
Treating a synthetic drug addiction can be done. It will take a multifaceted treatment programme that will address the mental, physical, and emotional aspects of recovery. Some of the treatment options can include:
Inpatient Care
Inpatient care can be pivotal in helping a person overcome drug addiction. While they are in a residential facility, a person will receive intensive addiction treatment. They'll also be in a controlled environment where they can focus on their recovery process. The support received in this setting can be very helpful for setting a foundation of lasting sobriety.
Individual Counselling
People who struggle with drugs also often struggle with their mental health. Individual counselling isn't just an important part of helping a person through addiction; it can also help them begin the process of improving their mental health, which can often cause addiction and worsen as a result of it. In one-on-one therapy sessions, the patient and therapist will address the underlying cause of the patient's substance use. Clients will also learn healthy coping mechanisms so they can manage their cravings outside of residential substance abuse treatment.
Group Therapy
Group therapy is another important part of drug rehab. In group therapy, people in recovery will connect with others who have similar struggles with the dangers of synthetic drugs. These sessions can be important because they allow someone to form a support system. It can also help them practice the coping skills they learn in individual counselling, sometimes involving setting boundaries with others.
You Can Build a Sober Future
Addiction can lie to people. It can make them think that their situation is hopeless and that there is no way to overcome it and live a healthy life. The truth, however, is just the opposite. Drug addiction can be overcome and managed. While many do not get the help they need, others find that they can retake control over their lives and have the ability to build a sober future. Start building a sober future today.
Last reviewed 2026-07-25. Next review 2027-07-25.
Treating synthetic drug addiction takes more than willpower
Three structured group sessions a day, individual therapy, and a seventeen module curriculum. Admission usually within days of the assessment.
Questions people actually ask
What counts as a synthetic drug?
Synthetic or designer drugs are made in a lab rather than derived from a plant, and they are often distributed illicitly for recreational use. They are not all alike: some are stimulants, some are depressants. Common examples include fentanyl, synthetic cannabinoids, bath salts and molly. They are difficult to enforce against, because a single change to a drug's formula can put it outside laws written to ban an earlier version.
Why is fentanyl considered so dangerous?
Fentanyl is a synthetic opioid that is 50 times stronger than heroin and 100 times stronger than morphine, which makes it an incredibly powerful pain reliever and also incredibly addictive. Alongside pain relief, relaxation and euphoria, it can cause drowsiness, nausea and respiratory depression. England has seen a rise in fentanyl use significant enough that it has become a risk to public health.
Are synthetic cannabinoids the same as cannabis?
No. Synthetic cannabinoids, sometimes referred to as spice or K2, are lab made substances created to resemble the effects of the cannabis plant on a chemical level, but their effects can differ. Short term effects include increased heart rate and blood pressure, agitation, anxiety or paranoia, and numbness or tingling. Restricted blood flow to the heart, seizures and heart attacks have also been reported.
What are the long term effects of synthetic drug use?
Dependence is among the most serious. Once dependent, a person may have withdrawal symptoms if they stop, which fosters regular use and leads to tolerance. Tolerance dulls the drug's effects, so many people increase their intake, which raises the risk of overdose, and overdoses are often fatal without immediate medical treatment. Many synthetic drugs also cause lasting cognitive and emotional difficulties, including trouble regulating emotions.
What does treatment for synthetic drug addiction involve?
It takes a multifaceted programme covering the mental, physical and emotional sides of recovery. Inpatient care provides intensive treatment in a controlled environment where someone can focus on their recovery. Individual counselling addresses the underlying cause of the substance use and teaches healthy coping mechanisms for managing cravings afterwards. Group therapy connects people with others facing similar struggles, builds a support system and gives space to practise those skills.
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