In recent years, heroin use has become significantly more dangerous due to contamination with fentanyl – a synthetic opioid estimated to be 50 times stronger than heroin. This shift in the drug supply has led to thousands of overdose deaths across Texas, many involving individuals who were unaware they were consuming fentanyl at all.
In Bexar County, synthetic opioid overdose deaths rose by 160% between 2018 and 2022, with fentanyl now involved in over 60% of opioid fatalities.
At San Antonio Recovery Center, we provide education, support, and evidence-based treatment to help individuals navigate the evolving risks of opioid use. Knowing what heroin is typically cut with is critical for safety and for starting a path toward recovery.
Street heroin is often a cocktail of unknowns, with substances added to mimic its color, texture, and effects. These “cutting agents” can be anything from harmless powders to highly toxic drugs. Some are chosen to increase the dealer’s profit margin by diluting the heroin. Others are used to manipulate the experience by intensifying the high, dulling the comedown, or making withdrawal even more brutal.
Cutting agents change how heroin behaves in the body. They alter how it’s absorbed, how it feels, how long it lasts, and in many cases, they dramatically raise the risk of overdose.
Below are four of the most common cutting agents found in heroin, each with its own risks and symptoms. Understanding these additives can save the life of you or someone you love.
Quinine is a bitter compound originally derived from the bark of the cinchona tree, best known for its use in treating malaria.
How did it end up in street heroin? Dealers often use quinine to mimic the bitter taste of pure heroin, giving the false impression that what an individual is using is stronger or uncut. Quinine can’t replicate heroin’s effects, but it can alter how the body processes it and introduce a host of its own medical risks.
When taken in high doses, which is possible when it’s unknowingly injected, quinine can lead to a condition known as cinchonism. Symptoms include ringing in the ears, nausea, dizziness, blurred vision, and even temporary deafness.
Lactose may seem harmless because it’s in many of the things we consume daily. However, injecting lactose is different than consuming it in food or beverages.
Lactose is cheap, white, and easy to dissolve, making it an ideal filler for dealers looking to bulk up heroin without changing its appearance. It doesn’t add to the high, but it does make a small amount of heroin look like a lot more. That deception can have serious consequences for the person using it. For one, injecting heroin cut with lactose can cause significant vein irritation or blockages, especially if the lactose isn’t fully dissolved or sterile.
When used repeatedly, lactose as a cutting agent can contribute to abscesses, collapsed veins, and infections, particularly if you don’t have access to clean needles or harm reduction supplies.
There’s also the issue of lactose intolerance, which affects roughly 36% of people in the U.S., including a much higher percentage among Hispanic and Black communities, both of which are disproportionately impacted by the opioid crisis.
Most people think of caffeine as the thing that wakes them up in the morning, not something laced into a street opioid. But in the underground drug market, caffeine has a dual purpose: it adds bulk to heroin, and it may subtly alter how the drug behaves in the body.
Caffeine is a popular cutting agent because it’s inexpensive and it’s white and powdery – a perfect match for heroin in appearance. But this common stimulant doesn’t just disappear once it’s injected or smoked. Instead, it interacts with heroin’s sedative effects in unpredictable ways.
Some people who have taken that heroin cut with caffeine report that the combination produces a quicker or more intense onset, particularly when smoked or “cooked” for injection. That’s because caffeine lowers the melting point of heroin, making it vaporize faster and hit the bloodstream more rapidly.
This combination – known as a speedball effect – puts stress on the heart and central nervous system. Caffeine revs the body up while heroin slows it down, creating a chemical reaction that can mask the signs of overdose.
Fentanyl is increasingly found in street drugs, sometimes intentionally added to heroin (“lacing”) to increase potency, and other times introduced unintentionally through contamination during handling and distribution. Most people using these substances are unaware of its presence.
Unlike typical cutting agents, fentanyl amplifies heroin’s effects. Even very small amounts (about the size of a grain of salt) can cause respiratory depression. Those consuming these substances, including those with higher tolerance, face increased risk.
Counterfeit pills and powders sold as heroin often contain fentanyl, making dosage unpredictable. This contamination has contributed significantly to the rise in opioid-related overdose deaths in Texas and nationwide.
The terms “cutting” and “lacing” are often used interchangeably, but they refer to different practices, both of which have important implications for safety.
Cutting refers to diluting heroin with other substances to increase volume. These can include inert fillers like lactose or potentially harmful agents such as quinine or talcum powder. The primary purpose is to stretch the supply to maximize sales, rather than to change the drug’s effects.
Lacing involves intentionally adding a more potent substance, often significantly stronger than heroin itself. Fentanyl is a common example. When heroin is laced with fentanyl, the potency and risk increase substantially. Sometimes this is sought for the stronger effect, but more often it occurs without the individual’s knowledge, increasing the likelihood of overdose.
In short, cutting changes the quantity, while lacing changes the strength—and both carry distinct risks.
Both practices make the drug more unpredictable and unsafe.
Below is a breakdown of more common cutting agents and the health risks they carry:
| Cutting Agent | Why It’s Used | Primary Risks |
|---|---|---|
| Quinine | Mimics heroin’s bitter taste and effects | Seizures, irregular heartbeat, kidney failure |
| Lactose | Inexpensive way to bulk up the supply | Tissue damage, infections, allergic reactions |
| Caffeine | Enhances stimulant effect | Increased heart rate, anxiety, increased risk of overdose |
| Fentanyl | Boosts potency, increases addiction | Respiratory failure, overdose, death — often without user knowledge |
| Talcum Powder | Cheap filler | Lung damage, vein blockages, chronic inflammation |
| Starch/Sugar | Adds weight, mimics powder texture | Infections, abscesses, inflammation |
| Benzodiazepines | Intensifies sedation | Blackouts, memory loss, high overdose risk |
| Detergents/Cleansers | Appearance match, low cost | Tissue corrosion, systemic poisoning, rapid organ damage |
| Crushed Pills | Added opioid or stimulant effect | Unknown interactions, overdose, toxicity |
Recovery is not only possible, it’s happening every day. With the right treatment, support, and commitment, people can (and do!) rebuild their lives after addiction.
At San Antonio Recovery Center, we believe that healing isn’t just about stopping substance use, it’s about reconnecting with yourself, your community, and your future.
We’re proud to serve the San Antonio community with a deeply rooted understanding of its people. And with the largest alumni network in the region, support doesn’t end after treatment. If you or someone you love is ready to take the next step, call us today at 866-957-7885 or click to learn more about our heroin rehab center. You are not alone. Recovery starts here.
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