Oxycodone tablets contain a semisynthetic opioid pain reliever derived from thebaine, a compound found naturally in the opium poppy. The active ingredient in most formulations is oxycodone hydrochloride, but what else is in the pill depends entirely on which product you’re taking. Some tablets contain only oxycodone, while others combine it with a second pain reliever or an ingredient designed to counteract side effects.
The Active Ingredient
Oxycodone hydrochloride is the salt form of oxycodone used in pharmaceutical manufacturing. It belongs to a class of drugs called opioid agonists, meaning it activates opioid receptors in the brain and spinal cord. When it binds to these receptors, it reduces the excitability of nerve cells involved in transmitting pain signals, which is why it’s effective for moderate to severe pain.
Your liver processes oxycodone using two main enzyme systems. The first handles roughly 45 to 50 percent of each dose and converts it into noroxycodone, a mostly inactive byproduct. The second converts about 10 to 19 percent of the dose into oxymorphone, a metabolite that is actually more potent than oxycodone itself. This is one reason people with genetic differences in liver enzymes can respond very differently to the same dose.
Oxycodone-Only Products
Some prescriptions contain oxycodone as the sole active ingredient. These come in two main forms: immediate-release and extended-release.
Immediate-release tablets dissolve quickly in the stomach and deliver the full dose over a short period. Extended-release tablets, like OxyContin, are engineered to release oxycodone gradually over many hours. The extended-release version uses a polymer system called RESISTEC, which makes the tablet extremely hard to crush. If dissolved in liquid, it turns into a thick gel rather than a solution. These physical properties exist specifically to make the tablet harder to misuse by crushing, snorting, or injecting.
Other extended-release products take different approaches. Xtampza ER uses tiny waxy microspheres (about 300 micrometers across) that smear rather than break apart when crushed, and their water-repelling surface limits how quickly the drug can be extracted in liquid. Roxybond, an immediate-release option, includes inactive ingredients that slow absorption if the tablet is tampered with.
Combination Formulations With Acetaminophen
Many oxycodone prescriptions, including Percocet, combine oxycodone with acetaminophen (the active ingredient in Tylenol). The two drugs work through completely different pathways, and together they can provide stronger pain relief than either one alone. In these tablets, the oxycodone dose is relatively small compared to the acetaminophen dose. Common Percocet strengths include:
- 2.5 mg oxycodone / 325 mg acetaminophen
- 5 mg oxycodone / 325 mg acetaminophen
- 7.5 mg oxycodone / 325 mg acetaminophen
- 10 mg oxycodone / 325 mg acetaminophen
The acetaminophen component is important to be aware of because it carries its own risks at high doses, particularly liver damage. If you’re taking a combination product, any additional acetaminophen from other medications (cold remedies, headache pills) adds to the total load on your liver.
Formulations With Naloxone
Some oxycodone products, available in certain countries, combine oxycodone with naloxone, an opioid blocker. This pairing sounds contradictory, but the naloxone serves a specific purpose: it counteracts opioid receptors in the gut to prevent constipation, one of the most common and persistent side effects of opioid use.
The reason this works without canceling out the pain relief is that naloxone has extremely low bioavailability when swallowed (only about 2 to 3 percent reaches the bloodstream). It gets broken down almost entirely during digestion and its first pass through the liver, so it stays active in the intestines but never reaches the brain in meaningful amounts. These tablets use a fixed 2:1 ratio of oxycodone to naloxone, available in strengths like 10/5 mg and 20/10 mg. The naloxone also serves as a mild abuse deterrent, because if the tablet is crushed and injected, the naloxone would reach the bloodstream intact and block oxycodone’s effects.
Inactive Ingredients
Beyond the active drug, every tablet contains inactive ingredients that hold the pill together, control how it dissolves, and give it its color and shape. Extended-release OxyContin tablets, for example, contain polyethylene oxide, a polymer added during the 2010 reformulation that gives the tablet its abuse-deterrent hardness and gel-forming properties. Other common inactive ingredients across oxycodone products include binding agents, coatings, and coloring agents, though the exact list varies by manufacturer and tablet strength.
Why It’s a Schedule II Drug
The DEA classifies all oxycodone-containing products as Schedule II controlled substances, alongside fentanyl, hydromorphone, and methadone. This is the most restrictive category for drugs that have accepted medical uses. It reflects the high potential for both psychological and physical dependence. In practical terms, this means oxycodone prescriptions cannot be called in by phone in most cases, cannot include refills, and require a new prescription each time.