Opioids are a class of drugs that bind to opioid receptors in the brain and spinal cord. They reduce pain and can cause euphoria. With repeated opioid use, the brain adapts, which can lead to dependence and opioid use disorder. When use stops, opioid withdrawal begins.
This guide explains heroin vs. fentanyl withdrawal in clear terms so you can recognize withdrawal symptoms, understand the timelines, and understand how evidence-based addiction treatment can help. For individualized heroin or fentanyl addiction care in Georgia, explore our opioid addiction treatment options near Atlanta.
Overview of opioid addiction
Opioid addiction, also called opioid use disorder, is a medical condition. Dependence develops because the body adjusts to the drug, needing more for the same effect. That change can progress to compulsive drug use. In 2024, national data showed that opioid overdose deaths had finally begun to fall from their all-time high, but the opioid crisis still claims tens of thousands of lives in the U.S. each year, especially with synthetic opioids.
Common opioids: heroin and fentanyl
- Heroin is an illegal opioid that converts to morphine in the body.
- Fentanyl is a synthetic opioid, far more potent than morphine. Much of the current supply is illegal fentanyl mixed with other drugs.
Heroin addiction and withdrawal
Causes of heroin addiction
Heroin activates mu opioid receptors, flooding reward pathways with dopamine. Genetics, chronic pain, trauma, and environmental stressors raise risk. Regular heroin use rewires motivation and stress systems, which increases risk for dependence and opioid use disorder.
Symptoms of heroin withdrawal
Heroin withdrawal produces both physical and psychological changes. Many people describe it as being like a severe flu.
Physical symptoms
- Muscle and bone aches, chills, sweating
- Runny nose, yawning, goosebumps
- Abdominal cramps, diarrhea, nausea, vomiting
- Pupil dilation, changes in body temperature, elevated resting pulse
Psychological symptoms
- Anxiety, irritability, insomnia
- Cravings, restlessness, low mood
These opioid withdrawal symptoms are uncomfortable, but withdrawal alone is rarely life threatening. Dehydration or breathing problems can cause serious complications, so medical support is recommended.
Timeline of heroin withdrawal
- Onset: usually within 12 hours after the last dose
- Peak: 24 to 48 hours with painful withdrawal symptoms and strong cravings
- Resolution: most acute symptoms improved by days 4 to 10, though sleep and mood can take a few weeks to normalize
After detox, reduced opioid tolerance raises the risk of overdose if use restarts. Expert detox care with appropriate transitions to ongoing treatment helps reduce this risk. Find out more about our outpatient addiction treatment options in Georgia.
Fentanyl addiction and withdrawal
Causes of fentanyl addiction
Fentanyl has rapid onset, high potency, and short duration. These drug effects reinforce repeat dosing. When a patient regularly uses fentanyl, the brain adapts quickly. Many people are exposed to illegal fentanyl in counterfeit pills or mixed with other drugs.
Symptoms of fentanyl withdrawal
Fentanyl withdrawal symptoms often resemble heroin withdrawal, but some people describe a more intense course.
Physical symptoms
- Sweating, goosebumps, chills
- Muscle cramps, bone pain, stomach cramps, diarrhea
- Nausea, vomiting, runny nose, watery eyes
- Changes in blood pressure, fast heart rate, sleep problems
Psychological symptoms
- Anxiety, agitation, insomnia
- Strong cravings, depressed mood
- Brain fog, irritability
Timeline of fentanyl withdrawal
The fentanyl withdrawal timeline varies with dose, duration, and whether other opioids are present. Symptoms may start within 12 to 30 hours after the last dose, peak by days 2 to 3, and improve within up to two weeks. Because fentanyl is highly lipophilic, it can linger in tissues after heavy use, which may prolong or complicate withdrawal.
Comparing heroin and fentanyl withdrawal
Similarities in withdrawal symptoms
Both cause opioid withdrawal symptoms that mimic severe flu, including aches, sweating, gastrointestinal upset, sleep disruption, anxiety, and cravings. Both can trigger dehydration, electrolyte loss, and severe withdrawal if untreated. The clinical picture of opiate withdrawal is similar across other opioids, too.
Differences in withdrawal symptoms
- Potency and exposures: Illegal fentanyl is potent, and small changes in dose can shift symptom severity.
- Duration and intensity: Heroin withdrawal often starts sooner, then improves over several days. Fentanyl withdrawal can feel more intense, and some individuals report severe symptoms lingering for an extended period, including persistent insomnia and anxiety.
- Precipitated withdrawal risk: Fentanyl’s tissue storage can raise the chance of precipitated withdrawal if certain treatment medications are started too soon.
Any severe withdrawal should be monitored by healthcare professionals who can manage symptoms and reduce risk.
Opioid detoxification process
Heroin detox process
Medical detox tracks vital signs, including body temperature, pulse, and blood pressure, and uses the clinical opiate withdrawal scale to rate severity. Supportive fluids, nutrition, and symptomatic medications help manage symptoms. Lab work may include a complete blood count and liver function tests, plus screening for other infections as indicated.
Fentanyl detox process
Fentanyl detox can take longer for some people. Care teams watch closely for severe withdrawal and adjust timing of medications to avoid precipitated withdrawal. Because of increased risk after detox due to reduced opioid tolerance, follow-up treatment must start right away. If you need a safe place to begin fentanyl detox in north-central Georgia, learn about our fentanyl addiction treatment in Atlanta.
Treatment options for opioid addiction
Medication-assisted treatment
Medication-assisted treatment is the standard of care endorsed by the Substance Abuse and Mental Health Services Administration (SAMHSA). The three FDA-approved options are buprenorphine, methadone, and extended release naltrexone.
- Buprenorphine is a partial opioid agonist. It binds tightly to mu receptors, suppresses cravings, and helps opioid withdrawal management. It is used to treat OUD in office settings and specialty programs.
- Methadone is a full agonist. It stabilizes opioid dependence, prevents severe withdrawal, and is dispensed in opioid treatment programs.
- Naltrexone is an opioid blocker. It is started after detox and supports relapse prevention for some patients.
Behavioral therapies
Counseling helps people learn coping skills, repair relationships, and build a strong support system. Cognitive behavioral therapy, motivational approaches, and contingency management can improve outcomes when combined with medications and case management.
Additional supports
Group therapy and family counseling reinforce recovery, reduce stress, and improve adherence to a treatment plan. Many programs also integrate care for co-occurring conditions and chronic pain, and they coordinate with primary care to address body-wide health needs.
Finding the right rehab center
Criteria for choosing a rehab center
Look for:
- Licensed programs with trained healthcare professionals
- Ability to start medical detox quickly
- 24-hour support during medical detox
- Onsite or coordinated behavioral therapies and recovery coaching
- Clear aftercare planning for next treatment steps
Look for centers that provide comprehensive addiction treatment, medications, and ongoing support. Review medical history, preferences, and goals with the team.
Find compassionate, integrated opioid withdrawal management in Atlanta
Opioid withdrawal is difficult, but it is treatable. Professional care reduces severe withdrawal, prevents serious complications, and lowers relapse risk.Recovery works best with ongoing medications, therapy, and community support. If you or a loved one in the Atlanta area will experience withdrawal or want to start heroin or fentanyl detox, Promises Atlanta is here to help. Review opioid addiction treatment options in Atlanta, GA or reach out at 888.442.9602 today.
