Introduction to Heroin

The word heroin comes from the German 'heroisch' which translates as 'heroic', widely speculated to be a referral to the 'heroic' effects it bestowed on the user.

Heroin is a derivative of morphine in which the 3- and 6- hydroxy groups have been acetylated, typically by condensation with acetic anhydride. In 1874 in an attempt to develop a non-addictive, and therefore safe, analgesic as an alternative to morphine, and was marketed by the German pharmaceutical company Bayer in the early 1900s as a 'cure' for morphine addiction, and even a cough remedy for children. Despite the original claims, history and science tell us that heroin failed to live up to it's expectations, as repeated administration inevitably led to increased tolerance, physical and psychological dependence, and eventually addiction.

Internationally, heroin abuse and addiction is considered to be a serious socio-economical problem. [7] Although it is still prescribed as a painkiller and to long-term opiate addiction in some EU countries, it is an illegal, controlled drug. Diacetylmorphine continues to be widely used in palliative care in the UK [8] as the risk of addiction is not particularly relevant in these cases.

Using Heroin

Due to the variations in quality and purity of heroin batches at street level (2-3% - 98%*), estimating a mean dosage is at best an approximation, and at worse dangerous. Many users new to the heroin experience will initially share with a more experienced user, either by snorting or smoking, and titrate the dose according to the initial effects.
Added to this the often unscrupulous drug dealers attempts to increase profitability by adding adulterants, or "cutting" the heroin with a variety of other pharmaceuticals, and/or inactive or dangerous substances, the issues of suggested doses for first time users becomes almost impossible.
Experienced users will also need to titrate their doses as tolerance increases, and more heroin is needed to produce euphoric effects.

Ways of administration

The onset of the effects of heroin is dependent on route of administration determined by bioavailability- or the percentage of the unchanged drug that enters the bloodstream. When a drug is injected intravenously, bioavailability is 100%. Other methods of administration decrease the amount of the drug which enters the systemic circulation due to incomplete absorption or first-pass metabolism via the liver. Studies have shown users subjective experience of the pleasure of heroin use is in part determined by the speed at which the blood level of the drug increases [1a].

Intravenous (I.V) Injection

Heroin can be injected directly into a vein, a practice colloquially termed ‘digging’ or ‘shooting up’. Users report the onset of an intense rush within 7 to 8 seconds of administration, as heroin rapidly passes the blood-brain barrier. Bioavailability is 100%.

Intramuscular (I.M) Injection

An injection directly into the muscle, with an onset within 5-10 minutes. Bioavailability is 85%.

Subcutaneous Injection

This method refers to injecting under the outer layer of the hypodermis, often referred to as ‘skin-popping’.


Heroin can be administered through nasal insufflation, commonly referred to as ‘snorting’, ‘railing’ or ‘banging’. Peak effects can be felt within 10-15 minutes, as the heroin is quickly absorbed into the bloodstream through the soft tissue in the mucous membrane.

A solution can also be sprayed, dropped, or squirted with an oral syringe containing no needle, into the sinus. Most effective when the user positions their body tactfully, letting the solution be fully absorbed by the sinus instead of dripping down the throat or out the the nose. This method is referred to as "water-lining" or "wet-lining".

Smoking or Inhaling

This method is also referred to as ‘chasing the dragon’ and involves gently heating the heroin on aluminum foil and inhaling the smoke and vapours through a tube. Heroin can also be smoked with tobacco in a rolled cigarette. Onset times are similar to insufflation, and similarly, bioavailability is around 52%.

Heroin inhalation is justified by users because of the risks of HIV and hepatitis infections.

This way of administration of heroin has been reported to cause toxic leukoencephalopathy. See "dangers of heroin"

Rectal Administration

A lesser-used method also known as "plugging", considered by users a safer alternative to injecting. Heroin is absorbed through the rectal membrane, and effects can be felt within 10-15 minutes and peak at around 30-50 minutes.

Oral Administration

Heroin is rarely taken orally, as onset of effects can take a minimum of 30 minutes, and users often report the absence of a intense ‘rush’ with this route of administration. Bioavailability decreases to 35%.

Although most first time users will smoke heroin, this can often progress to intravenous use when heroin purity or tolerance reduces the effect of the drug when smoked, forcing users to switch to IV use; where the least amount of drug can be used for maximum effects.

Effects of Heroin

The effects of heroin include euphoria, a sense of warmth and well-being, a feeling of being disconnected from the real world, drowsiness, relaxation, drooping eyelids, somnolence. These effects can last for several hours. Following the initial rush of euphoria, the user may become very drowsy and relaxed, slipping in and out of consciousness in an alternately wakeful and drowsy state. This is known as “nodding” or “gouching”. Mental functioning becomes clouded, and the ability to complete simple tasks may be compromised. Other effects include slowed and slurred speech, a dry mouth, itchiness, constricted (or “pinned”) pupils, nausea, vomiting and constipation. Paradoxically to the common sedative effects, some new heroin users report that the drug gives them a feeling of increased energy. Some artists and writers have claimed that their heroin use provided them with bursts of creativity, but many other users firmly believe that the drug stems artistic and creative talent.

If a withdrawing addict uses heroin, on administration they will feel a rush of instant relief, euphoria, happiness, analgesia and lack of worry. When addiction, tolerance and dependence develop, an addict will require heroin to be able to even function properly in normal, day to day life. In this situation, using heroin serves mainly to restore normality, and to ease the pain of withdrawal. As dependence develops, as does a tolerance to some of the effects of heroin, such as its sedative effects, itching and nausea. It seems that tolerance does not have a great bearing on constipation, however, and many long term addicts report ongoing problems with constipation.

Heroin is a central nervous system depressant. This accounts for its sedative effects, as well as lowered blood pressure, depressed respiration and slowed, shallow breathing. The drug also works as a very effective analgesic, acting as a strong pain killer.

It may be difficult to rouse someone who is nodding as a result of taking heroin, but they should be responsive to audio and physical stimuli. If it is not possible to gain a reaction from a heroin user, and they are unresponsive to their name being called or to physical stimuli, then medical help is required, as it is likely that they have overdosed.

Negative effects associated with heroin use include a high risk of dependence, addiction and withdrawal. There is a high risk of overdose if one injects, this is the most dangerous route of administration. It must also be noted that it is still very possible to overdose through snorting heroin, but is less likely than if one injects. Smoking heroin is the least dangerous route of administration, but for non tolerant users there is still a small risk of overdose, although it is less likely that an overdose via this method of administration would be deadly.

If a heroin user injects, a wide range of injection-related health risks must also be taken into account. Although much safer than injecting, smoking and snorting are by no means harmless. The normal risks connected to these route of administration exist, such as respiratory problems for smoking, and sinus infections for snorting. For a more comprehensive explanation of the risks associated with heroin use, please see 'The Dangers of Heroin'.

Combinations with Heroin

Ideally, heroin should not be combined with any other psychoactive drug, but realistically it is understandable that many users will do so, thereby increasing the risk of complications and death. Research by the Drug Abuse Warning Network reported an average of 2.7 drugs were present in fatal overdose cases, and although no single drug was found at a lethal dose, the synergistic effects of combination can themselves be lethal. [5] Some of the drugs more commonly used in combination with heroin include:


Usually injected intravenously with heroin- a practice known as "speedballing"- this combination is incredibly euphoric and has been described by many users as a full body/mind orgasm. Speedballing has a reputation for inducing an intense and powerful high. However, it is a very dangerous combination, as the use of a depressant (heroin) and a stimulant (cocaine) concurrently can cause major cardiac problems, up to and including heart attack and fatal overdose. In recent years, Hollywood actors John Belushi and River Phoenix died as a result of abusing this combination.

Alcohol and benzodiazepines

The other most common combination among users who want to get really intoxicated, and are unaware of the dangers. Heroin, benzodiazepines and alcohol are all central nervous system (CNS) depressants. Mixing CNS depressants can be incredibly dangerous due to combined depression effects on the circulatory and respiratory systems. The user's breathing and circulation can slow to a stop, leading to respiratory and/ or cardiac arrest. Additionally, many benzodiazepines cause retrograde amnesia, meaning the user will forget they already took three pills, and soon a bottle of fifteen will be gone when the user still thinks they only took three. The majority of "heroin overdose" deaths are actually polydrug overdoses, and the additional drugs are usually benzodiazepines and/or alcohol, and sometimes cocaine.

Various Psychedelics, etc.

The psychedelic experience tends to overpower most aspects of heroin. If an addict is starting to get sick from lack of heroin during a trip, a dose should be administered (often, even long-time injectors will need help in this situation) or else there is a risk of the trip going bad, but recreationally mixing psychedelics or empathogens with heroin is generally considered a waste of heroin.


Can add a pleasant floating feeling and euphoria to the already floaty and euphoric heroin high, but only in users that enjoy marijuana. Many a comfortable, nodding heroin addict has had his/her high ruined by an anxiety attack brought on by a few hits of marijuana.

Different Uses for Heroin

Pharmacology of Heroin


LD50 (freebase) [1] :
Mice : 59 µmol/kg intravenously

When someone takes heroin, either by means of injection, insufflation or smoking, the drug enters the bloodstream, then travels towards the brain, hitting hits the blood-brain barrier, already having been converted to 6-mono-acetylmorphine (6MAM) through hydrolysis. This compound, unlike pure morphine, is lipid-soluble and races through into the brain with almost no delay. Then the 6MAM rapidly breaks down into morphine.

In the brain, the morphine can get to work by stimulating the mu (µ) opioid receptors. One of the main ways in which heroin creates its effect is by simulating the natural neurotransmitters (called the endogenous opioids, which include endorphins) in the brain. These neurotransmitters are very similar to opiates, and so the receptors for these natural opiates will accept both the natural and artificial varieties. The receptors are located on neurons containing γ-aminobutyric acid (GABA) neurotransmitters. GABA proteins are involved in the release and inhibition of dopamine.

Normally the GABA neuron receives a signal and releases a large number of neurotransmitters, these bind to receptors on the dopamine neuron and allow the Cl¯ waiting in the synaptic cleft to enter the dopamine neuron. This signals the neuron to release only a small, specific, set amount of dopamine, which in turn binds to another neuron, continuing the neural pathway, and leads to "normal" feelings of happiness, contentment or pleasure.

The presence of morphine significantly alters this pattern. When the morphine binds to the opiate receptor on the GABA neuron it represses the release of the GABA neurotransmitters, this in turn reduces the amount of Cl¯ that is allowed into the dopamine neuron. Without the Cl¯ to inhibit it, the neuron releases a large, uncontrolled amount of dopamine, leading to the feeling of euphoria and extreme contentment.

Opiates also depress nerve transmission in sensory pathways of the spinal cord and brain that signal pain. Release of enkephalins suppresses the transmission of pain signals. Little is to be gained by having the perception of pain increase indefinitely in proportion to the amount of damage done to the body. Beyond a certain point, it makes sense to have a system that decreases its own sensitivity in the case of massive, intractable pain. By binding to enkephalin receptors, opiates like morphine enhance the natural pain-killing effects of enkephalin neurons. This explains why opiates are such effective painkillers. The brain centers which controlling coughing, breathing, and intestinal motility are also inhibited by opiates. Mu (µ) opiate receptors are also found on the cells in the medulla oblongata that regulate breathing. This accounts for the suppressive effect which opiates have on respiration.

Heroin is exceedingly addictive, quickly producing tolerance and dependence. Opiate tolerance can be partly explained as a homeostatic response that reduces the sensitivity of the system, in order to compensate for continued exposure to high levels of morphine or heroin. When the drug is stopped, the system is no longer as sensitive to the soothing effects of the enkephalin neurons and the pain of withdrawal is produced.

One of the reasons why coming off heroin can be so painful is because the user will have used up a huge quantity of dopamine in one rush. Thus their body has to make more before it can begin to release it normally again. When a person becomes an addict, this problem only becomes worse, each use of heroin adding to the last. Finally, when the cells that create dopamine are put under a significant amount of stress, they will start to shut down, producing less dopamine. This is one of the reasons why withdrawal from heroin is so extreme.

A substantial portion of the physical symptoms seem to depend on the activity of a part of the brainstem called the locus coeruleus. Opiates depress this area and it would therefore be expected to become hyperactive during withdrawal. The locus coeruleus is an important center in the brain's fear-alarm system, and it's “fight or flight” response, and such hyperactivity would be consistent with the marked anxiety and agitation that withdrawing heroin addicts experience.

Noradrenaline is a neurotransmitter which is produced in the locus coeruleus. By stimulating receptors in the body, noradrenaline helps control things like the speed food moves through the digestive system and the production of tears and saliva. Opiates such as heroin reduce the amount of noradrenaline produced, almost completely blocking its production. Because of this, the locus coeruleus has to work really hard to produce any at all. This suppression by opiates of noradrelanine production, and the resulting low noradrenaline levels, contribute towards many of the side effects of long term opiate use, including the low blood pressure, constipation and dry mouth that affects many people who use drugs like heroin.

When an addict suddenly stops taking heroin, it takes a while for the locus coeruleus to adapt, and there is a delay before it realizes that it doesn't have to carry on working so hard. Until it does (which usually takes about 10 to 14 days), the withdrawing addict will produce masses of noradrenaline. This causes many physical withdrawal symptoms like vomiting, diarrhea, sneezing, watery eyes, hypersalivation, yawning and runny nose, as well as high blood pressure and respiratory rate.

Trying heroin once is not enough to make a person physically addicted. The technical definition of an addict is "someone who is physiologically dependent on a substance [and] abrupt deprivation of the substance produces withdrawal symptoms." When the body needs to have a substance in order to function, the user has become "physiologically dependent". This means that the user will go through withdrawal if they suddenly stop taking that drug. The chemical actions that lead to withdrawal come about when heroin has been used so frequently, and for so long, that the body cannot function when only being supplied with normal, natural levels of dopamine. If heroin is only taken once the user may suffer a "low" after taking the drug, due to the fact that a large amount of their dopamine has been used up, but their neurons have not become permanently damaged or adjusted to the drug, and do not require it to operate properly. Thus the person is not physically addicted. When someone is physically addicted, and they stop taking heroin “cold turkey”, all the physiological and neurological systems that have been repressed and suppressed during their addiction go into overdrive, accounting for the many awful symptoms that are suffered during heroin withdrawal.

Chemistry of Heroin

Column 1 Column 2
Systematic (IUPAC) name: (5α,6α)-7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol 3,6-diacetate
Synonyms: heroin, diamorphine, acetomorphine, diacetylmorphine
Molecular Formula: C21H23NO5, C21H23NO5.HCl.H2O (hydrochloride monohydrate), C21H23NO5.CH3I methyl iodide
Molar mass: 369.42 g/mol, 423.89 g/mol (hydrochloride monohydrate), 511.35 g/mol (methyl iodide)
CAS Registry Number: 561-27-3[2]
Melting Point: 173°C, 243-244°C (hydrochloride monohydrate), 252°C (methyl iodide)[1]
Boiling Point: 272-274°C @ 12 mmHg[1]
Flash Point: no data
Solubility: Freebase 1 g dissolves in 1.5 mL chloroform, 31 mL alcohol, 100 mL ether, 1700 mL water; slightly soluble in ammonia or sodium carbonate solution; soluble in alkalies (/// need to actualize the term). Hydrochloride monohydrate soluble in 2 parts water, 11 parts alcohol; insoluble in ether[1]
Additionnal data: none
Notes: Freebase aspect arthorhombic plates, tablets; crystallized from ethyl acetate; decomposes by boiling with water; turns pink and emits acetic odor on prolonged exposure to air. Hydrochloride monohydrate aspect : fine crystals. Methyl iodide aspect : needles[1]

The dangers of Heroin

Deadly heroin overdose

Tolerance to heroin can differ so much, that a normal dose of heroin for the user that has built up tolerance, can be a deadly dose to the user that has not built up tolerance. A user that has gone trough withdrawals quickly looses his tolerance to heroin. The risk of overdose becomes even higher due to the fact that street heroin differs in purity between 3% - 98%. Purity of heroin is unknown to the user when illicitly sourced. It is easy to take a higher dose than intended and to misjudge ones tolerance. Such mistake can cause a deadly heroin overdose. Sadly fatalities from heroin overdoses are a common fact and most heroin users remember a lot of users that suffered this fate.

Toxic leukoencephalopathy

Progressive spongiforme leukoencephalopathy has been reported consecutive to heated heroin inhalation (chasing the dragon). This condition is relatively rare, but it can have serious consequences including death, and incomplete recovery has also been reported[3].

The precise cause and mechanism of heroin-induced leukoencephalopathy is still unclear. Raised intracerebral lactate concentration and good response to coenzyme Q treatment suggest that a metabolic mitochondrial dysfunction due to a toxic agent could be responsible for the condition[3].

Contaminants present in some heroin batches could hold some responsibility, as reported cases are usually found as clusters confined in restricted regions and periods[3]. However, some cases have been reported consecutive to inhalation of pure opiates[NEEDS REF], indicating that the opiate itself is responsible for leukoencephalopathy. It has been noted that leukoencephalopathy develop among users who heat heroin, therefore the toxic agent responsible might be produced from heating heroin[3].

Toxic leukoencephalopathy can occur both after short term and long term heroin use[3].

The treatment of heroin-induced leukoencephalopathy consists in antioxidant therapy, consisting in coenzyme Q supplemented with vitamins C and E[3].

Heroin laced with toxic substances

Heroin and most other opiates are relatively safe if known quantities of pharmaceutical grade preparations are used, however heroin illicitly sourced may be cut with all manner of things that are detrimental to health. To cite an extreme example. recently (as of 2010) in the UK a health warning was issued about batches of heroin contaminated with anthrax. Also, even if one assumes the powder cannot be more than 100% heroin and makes calculations accordingly there is still a risk of overdose since fentanyl, a much stronger opiate, weight for weight, could have been added to up the strength. Heroin laced with fentanyl or Fentanyl sold as heroin frequently leads to deaths.

Heroin lifestyle dangers

There are also a more nebulous set of dangers that can perhaps best be called "lifestyle dangers" such as poor diet, homelessness, problems from unsafe injecting techniques, lack of personal hygiene that often, but not inevitably, go with long term heroin use. The intravenous (IV) route of administration for heroin greatly increases the risk factors associated with its use. IV users need consider a whole new range of serious health problems, including infections and abscesses as a result of “missed hits”, blood borne viruses including hepatitis and HIV, necrosis of tissue caused by inadvertent arterial injection, and deep vein thromboses. Using lemon juice to acidify heroin for injection can lead to infection of the heart (endocarditis) and eyes (candidal endopthalmitis).[6]

Heroin addiction

The final danger is of course the development of dependence and addiction. There is some disagreement as to how quickly a true physical dependence can develop, but daily use over a period of weeks or months will eventually lead to dependence. It seems addiction to heroin can re-establish itself particularly quickly after a user has once been addicted. Often the onset of heroin addiction, or opiate addiction of any kind, is insidious. Anyone wishing to use heroin should be very aware of this, since many addicts start off trying it "just the once", or "only on weekends". It is well worth considering the risks of addiction before anyone decides to try heroin "just the once".

Producing Heroin

Heroin is usually produced by reacting morphine with acetic anhydride[4].

Forms of Heroin

There are several different types of heroin. Heroin #3, sometimes referred to as H3 or base heroin, is mostly found in the UK and Europe, as well as across other countries internationally. This is a more basic form of heroin and is usually found as a fine powder, ranging in tone from off-white to medium brown. Heroin #3 needs to be mixed with an acid in order to make it soluble for use via injection. Citric acid and ascorbic acid (vitamin c) are often used for this purpose. The following video describes the process of dissolving heroin base with citric: How much citric? Since ascorbic acid (vitamin c powder) is less strong than citric acid, slightly more is needed to dissolve the same amount of heroin. This means that there is a greater margin for error; meaning, if someone uses slightly too much, it won't have as great of an impact on the acidity compared to the same amount of excess citric acid.

Heroin #3 is also commonly used via smoking or, "running" on foil", which is sometimes also referred to as
"chasing the dragon".

Heroin #4 (AKA H4 or china white) has gone through a few more steps in its production and it is suitable for injection "as is". It is the hydrochloride version which means that it readily dissolves in water and requires no added citric acid. It is most commonly used via injection or insufflation. It is not desirable to smoke H4 due to the high melting and boiling points. H4 is usually a light beige / off white to a very plain or stark white color.

Heroin #4 is most commonly found on the East Coast of the United States.

Black tar is very refined opium, treated with glacial acetic acid and/or acetic anhydride (most often acetic anhydride). It is very, very different from raw opium latex. The active constituents are usually diacetylmorphine, unreacted morphine, 6-monoacetylmorphine and acetylcodeine (among other non CNS-active quinolines). The reason why tar tastes like vinegar, is because of the acetic anhydride, which resembles the taste and smell of vinegar. It basically is slightly more refined than heroin #3, but not as much as heroin #4. This type of heroin is most commonly used via injection or smoking ("chasing the dragon"). It is commonly found on the West Coast of the United States.

China White

Legal status of Heroin

United Nations


In the United States, heroin is a schedule I drug according to the Controlled Substances Act 1970. It is illegal to buy,possess, manufacture or sell without a DEA license.


In the UK, although heroin is available under prescription, it is illegal to buy, sell or possess without a license. Heroin is a Class A substance under the Misuse of Drugs Act 1971. Possession is punishable by up to 7 years in prison and/or an unlimited fine. Supply, intent to supply, production and trafficking can be punishable by up to life in prison, and/or an unlimited fine.

History of Heroin

English research-chemist C.R.Wright discovered the heroin compound in 1874 when he was attempting to develop a pain-killer as powerful, yet less addictive, than morphine. Whilst testing & heating various acids with morphine, he combined the opiate with acetic anhydride, which produced the powerful acetylated morphine, diacetylmorphine.
It was manufactured by Bayer Pharmaceutical eighteen years later, after they independently re-synthesized morphine, without knowing that C.R.Wright had written off it's potential years before, and it gained widespread acceptance by the medical profession in it's early uses as a morphine substitute, cough suppressant and 'aid for female problems'. Embarrassingly, Bayer did not yet have the scientific evidence to realize that heroin is rapidly metabolized into morphine by the liver, and as such acts as a much quicker acting form.
Sale increased as time went on and by 1913 heroin was available to users in capsules, pastilles, diluted in liquids, as a powder, or in an injectable form.
Throughout the early 1900s positive reports of heroin's non-hypnotic and non-addictive powers began to be replaced with serious concerns regarding the spread of "heroinism" (2) and patients' developing tolerance.
Inevitably, the following year the U.S government passed the Harrison Narcotics Tax Act to control the sale and distribution of opiates, and made it illegal to use without prescription.
"In 1924 the United States Congress banned its sale, importation or manufacture. It is now a schedule I substance, which makes it illegal for non-medical use in signatory nations of the Single Convention on Narcotic Drugs treaty." (3) Conversely, it's believed that the head of Bayer's pharmacological laboratory, Herr Dreser, himself died a heroin addict.(4)


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