Lacing (drugs)

Lacing is the act of adding one or more substances to another. Some street drugs are commonly laced with other chemicals for various reasons, but it is most commonly done so as to bulk up the original product or to sell other, cheaper drugs in the place of something more expensive. Individuals sometimes lace their own drugs with another substance to combine or alter the physiological or psychoactive effects.
Reasons for lacing.
Illegal drug trade.
Drugs may be sold to end users who are unaware they have been laced or are unaware what was used to lace them. At various points in the supply chain, in order to maximize profitability, many drugs are adulterated with cutting agents. Substances with similar physical and/or chemical properties can be used so the end product most closely resembles what it is purported to be. Inert substances with similar physical properties can be used to increase weight without changing the look and feel. Less expensive or easier to obtain compounds with similar chemical properties may be used to lace heavily adulterated drugs while still maintaining some psychoactive potency.
Mickey Finn.
In slang, a Mickey Finn—or simply a Mickey—is a drink laced with a psychoactive drug or incapacitating agent (especially chloral hydrate) given to someone without their knowledge, with intent to incapacitate them.
Poly drug use.
Drugs may also be laced with the end user being made aware of the lacing. In this case, rather than as an adulteration, the lacing is intended to make the product more desirable. Sometimes less potent, often less expensive drugs, are laced with a small amount of a more potent, often more expensive drug. This may be used to facilitate the ingestion of drugs or to allow the simultaneous ingestion of multiple drugs. Cigarettes laced with PCP allow users to take in the liquid PCP through smoking and some multi drug users report intentionally buying marijuana laced with methamphetamine.
Commonly laced substances.
Street drugs.
Depressants.
Heroin.
Heroin is commonly cut with quinine, caffeine, dimethocaine, procaine, lactose, inositol, dextrose, mannitol, and starch.
Other opioids are sometimes sold as heroin or cut with heroin. Fentanyl sold as or laced into heroin has made the news in the past due to the numerous fatalities it causes when it appears on the market. Recently, Fentanyl and close analogues have been produced in pure powder form for very cheap. Dealers may cut with or sell heroin with Fentanyl due to the street cost of Fentanyl versus the cost of heroin. The potency of such mixtures (especially if made carelessly) can be far above that of pure heroin, and users frequently overdose due to this. Gray death is a street drug in the United States. Samples have been found to contain the designer drug U-47700, heroin and opioids including fentanyl and carfentanil.
Stimulants.
Stimulants are drugs that speed or give a mental boost to the consumer
Cocaine.
The most common cocaine adulterants found in 1998 in samples in Rome, Italy were lidocaine and caffeine. Cocaine is sometimes mixed with methylamphetamine, methylphenidate, and ephedrine, but is usually mixed with non psychoactive chemicals such as mannitol, inositol, pectin, glucose, lactose, saccharin, white rice flour, and maltodextrin. Other 
of agranulocytosis, including 2 deaths, according to an alert from the Substance Abuse and Mental Health Services Administration (SAMHSA).
The emergence of fentanyl-laced cocaine has led to an increase in cocaine overdose fatalities in New York City. 
Methamphetamine.
MSM is sometimes used as a cutting agent for illicitly manufactured methamphetamine.
Psychedelics.
Cannabis.
Cannabis products are usually laced with synthetic cannabinoids:
Less common psychoactive substances used to adulterate cannabis:
Weight cutting agents:
Ecstasy.
Black market ecstasy pills are frequently found to contain other drugs in place of or in addition to methylenedioxymethylamphetamine (MDMA). Since the slang term "ecstasy" usually refers only to MDMA, any pill which contains other compounds may be considered adulterated. 3,4-Methylenedioxyamphetamine (MDA), methylenedioxyethamphetamine (MDEA), amphetamine, methylamphetamine, benzylpiperazine (BZP), trifluoromethylphenylpiperazine (TFMPP), caffeine, ephedrine, pseudoephedrine, and dextromethorphan (DXM) are all commonly found in pills being sold as ecstasy. Less common drugs in ecstasy include diphenhydramine, acetaminophen, 5-MeO-DiPT, 2C-B, procaine, and phencyclidine (PCP). Ecstasy pills sometimes contain dimethylamylamine to increase its stimulant effects. Ecstasy pills might also contain a low dose of 2C-I to potentiate its euphoric effects. Pharmaceutical pills are sometimes sold as ecstasy, as well as pills that contain no psychoactive chemicals at all. Ecstasy sometimes contains 10 mg to 20 mg of baclofen to reduce overheating caused by ecstasy. "para"-Methoxyamphetamine (PMA or "Dr. Death", a drug that causes so much overheating that it can kill within 40 minutes) is sometimes sold as ecstasy. There is one published case of an ecstasy tablet being adulterated with 8 mg of strychnine, a toxic alkaloid which was used in very low doses (less than 1 mg) as a stimulant and performance-enhancing drug in the past. Recently, several groups advocating for drug safety through education have made reagent testing products available to confirm what substances there are.
LSD.
LSD is virtually never laced with other chemicals, but other lysergamides such as ALD-52 are sometimes sold as LSD-25. DOB, DOI, and other closely related drugs are sometimes sold as LSD. Several other highly potent hallucinogens such as Bromo-DragonFLY or 25I-NBOMe can be found in the form of blotters. LSD is also tasteless in normal dosages, so detection is only possible after ingestion or reagent testing. For these reasons, it is not uncommon to find blotters sold as LSD completely devoid of psychoactive substances.
Prescription Medication.
As the sources of prescription medication on the street are not verifiable through legitimate channels, misrepresentation of prescription medications is a common practice.
Testing.
Reagent testing.
Reagent testing kits are available online and also sold at some head shops. These kits claim to be able to identify common adulterants in ecstasy.
Professional lab tests.
There are services available for testing the contents of an ecstasy pill that can tell the user what chemicals are contained in the pill and at what ratio. The results are then posted on their website along with every other pill that they have tested. The tests are considered to be highly accurate. Their services were at one time free, but when they ran out of funding they had to charge a fee for every pill tested.