Heroin Addiction

How heroin works in the brain

Heroin is a semi-synthetic opioid derived from morphine, itself extracted from the opium poppy. Chemically, heroin is diacetylmorphine, and its distinguishing pharmacological feature is rapid transit across the blood-brain barrier, faster than morphine itself, which produces an intense and abrupt euphoric surge. It acts as a potent agonist at mu-opioid receptors, the same receptors targeted by the brain's own natural endorphins and by prescription painkillers.

With repeated use, the brain's opioid system adapts by reducing its own natural opioid production, downregulating receptor density, and recalibrating reward sensitivity. The result is tolerance (needing more drug to achieve the same effect), physical dependence (the nervous system requires the drug to function normally), and withdrawal when use stops. Over time, use is no longer about producing euphoria; it becomes about avoiding the agony of withdrawal. The National Institute on Drug Abuse classifies heroin use disorder as a chronic, relapsing brain disease.

Many people with heroin use disorder began with prescription opioids. The National Survey on Drug Use and Health consistently finds that a significant proportion of people who use heroin report using prescription opioids first, with the transition often driven by cost and availability once tolerance made prescription pill quantities unaffordable.

The current supply: fentanyl contamination changes everything

The heroin supply in the United States has been dramatically reshaped by illicitly manufactured fentanyl. Law enforcement and public health surveillance consistently find that the majority of samples sold as heroin now contain fentanyl, fentanyl analogues, or both, sometimes in place of heroin entirely. This has multiple clinical and life-safety implications.

Someone who believes they are taking heroin with a familiar dose may actually be taking a fentanyl formulation with unpredictable concentration. Fentanyl is approximately 50 to 100 times more potent than morphine, and hot spots, uneven mixing in a batch, mean that one portion can contain a sub-threshold dose while another portion of the same batch is lethal. This is why having naloxone available and avoiding solo use are now critical harm reduction practices for anyone who uses opioids.

From a treatment perspective, fentanyl contamination affects buprenorphine induction timing and may require different medication dosing than historical heroin dependence. Clients entering treatment for heroin use disorder at The Archangel Centers are assessed with this clinical context in mind.

Signs and symptoms of heroin use disorder

Heroin addiction often progresses faster than families expect, and the physical signs can be masked by the person's efforts to appear normal. Recognizing the warning signs early creates the best chance for intervention before an overdose.

• Drowsiness, nodding off at inappropriate times, slurred speech
• Constricted (pinpoint) pupils even in dim lighting
• Track marks, bruising, or scarring at injection sites; wearing long sleeves in warm weather
• Unexplained burns or foil residue from smoking
• Withdrawal symptoms when not using: sweating, chills, muscle and bone aches, vomiting, restless legs
• Running out of money with no clear explanation; missing valuables from the home
• Social withdrawal, loss of interest in previous activities and relationships
• Continued use despite overdoses, near-misses, or serious consequences
• Keeping naloxone nearby or frequent trips to the emergency room

Heroin withdrawal: timeline and experience

Heroin withdrawal is among the most physically brutal of all substance withdrawal syndromes, though it is rarely fatal on its own. The fear of withdrawal is one of the most powerful drivers of continued use and one of the most significant barriers to seeking help. Providing accurate information about what to expect, and about the clinical tools available to manage it, is important for people considering treatment.

Withdrawal from heroin typically begins within eight to twenty-four hours of the last dose, depending on the preparation and purity (fentanyl-contaminated heroin may behave more like fentanyl). Symptoms peak within thirty-six to seventy-two hours and include muscle aches and bone pain, profuse sweating, goosebumps, nausea and vomiting, diarrhea, severe insomnia, restless leg sensations, yawning, pupil dilation, elevated heart rate, anxiety, and overwhelming cravings. Most acute symptoms resolve within five to ten days.

Post-acute withdrawal syndrome (PAWS) can follow acute withdrawal for weeks to months, characterized by persistent low mood, anhedonia, sleep disruption, cognitive difficulties, and intermittent cravings that are particularly strong in response to people, places, or emotions associated with past use. Medication-assisted treatment addresses both phases. This page is educational and not dosing or medical advice.

Medical risks of heroin use beyond overdose

Beyond the acute overdose risk, long-term heroin use carries serious medical consequences that require clinical attention during and after treatment.

• Injection drug use transmits HIV, hepatitis C, and hepatitis B; new injection equipment programs and testing are important harm reduction measures
• Bacterial infections including endocarditis (heart valve infection), abscesses, and sepsis from non-sterile injection
• Collapsed veins and venous damage from repeated intravenous use
• Pulmonary complications including aspiration pneumonia in overdose survivors
• Nasal tissue damage and increased respiratory infections from intranasal use
• Chronic constipation and bowel dysfunction from long-term opioid use
• Hepatitis C is now curable with over 95 percent success rates using direct-acting antivirals; The Archangel Centers connects clients with testing and treatment resources

Treatment for heroin use disorder

The Archangel Centers is an outpatient provider offering PHP, IOP, and standard outpatient care in New Jersey and North Carolina. We do not provide medical detox, inpatient, or residential rehab. When medically supervised withdrawal is needed first, we coordinate detox placement with licensed partners, then welcome clients into our outpatient programs once they are stable.

Medication-assisted treatment combined with behavioral therapy is the most evidence-based approach for heroin use disorder. NIDA, ASAM, and the Surgeon General all endorse MAT as the standard of care, citing its ability to reduce overdose deaths, reduce illicit drug use, and support long-term recovery. The Archangel Centers offers both buprenorphine (Suboxone, Sublocade) and naltrexone (Vivitrol). A psychiatric provider evaluates each client to determine which medication, if any, is clinically appropriate.

• Buprenorphine (Suboxone, Sublocade): partial opioid agonist, suppresses withdrawal and cravings, ceiling effect limits overdose risk
• Naltrexone (Vivitrol): opioid antagonist, blocks opioid effects, requires completion of withdrawal before starting
• Naloxone education, take-home access, and overdose safety planning
• Hepatitis C testing and linkage to curative treatment
• CBT, DBT, and trauma-focused therapy including EMDR
• Family therapy and family education programming
• Dual diagnosis care for depression, anxiety, PTSD, and other co-occurring conditions
• PHP, IOP, and standard outpatient continuing care

Getting started: practical steps

The first step is a confidential assessment call. At The Archangel Centers, clinical staff assess each client's history, current use, any co-occurring health or mental health needs, and logistical circumstances to recommend the right level of care. Insurance benefits are verified for free, usually within minutes, and real out-of-pocket costs are explained before any commitment.

Same-week placement is often available. If medically supervised withdrawal is needed first, we coordinate that placement immediately rather than leaving the client to navigate it alone. For family members calling on behalf of a loved one, our team can discuss options, resources, and how to approach the conversation with someone who may not be ready.