Percocet and Vicodin are both prescription painkillers that combine an opioid with acetaminophen (the active ingredient in Tylenol), but they contain different opioids. Percocet contains oxycodone, while Vicodin contains hydrocodone. That single difference affects how strong each pill is, how your body processes it, and which side effects you’re more likely to experience.
Both are classified as Schedule II controlled substances by the DEA, meaning they carry a high potential for abuse and dependence. Despite their similarities, they’re not interchangeable.
Active Ingredients
Each tablet of either drug pairs an opioid with acetaminophen, which boosts the opioid’s pain-relieving effect. The opioid component is the key difference:
- Percocet: oxycodone + acetaminophen
- Vicodin: hydrocodone + acetaminophen
Both come in tablets containing 2.5 to 10 mg of the opioid, combined with 325 to 750 mg of acetaminophen per tablet. Your prescription label will list both amounts, and paying attention to the acetaminophen number matters for liver safety (more on that below).
Which One Is Stronger?
Milligram for milligram, oxycodone is about 1.5 times more potent than hydrocodone. In pain-conversion terms, 10 mg of oxycodone delivers roughly the same relief as 15 mg of hydrocodone. So a 5 mg Percocet tablet packs more opioid punch than a 5 mg Vicodin tablet.
That said, when researchers tested the two drugs head-to-head in emergency room patients with bone fractures, both 5 mg doses produced equivalent pain relief at 30 and 60 minutes. The practical difference in strength matters more at higher doses or over longer treatment courses, where oxycodone’s extra potency can add up.
How Fast They Work and How Long They Last
Both medications are immediate-release formulations designed for short-term pain. Hydrocodone reaches its peak concentration in the blood within about one hour after swallowing a tablet, and oxycodone follows a similar timeline. A single dose of either drug typically provides relief for four to six hours, which is why prescriptions usually call for dosing at that interval.
If you feel like one wears off faster than the other, that’s worth mentioning to your prescriber, since individual metabolism plays a big role in how long the effect lasts.
Side Effects
The two drugs share the standard opioid side effect list: nausea, vomiting, drowsiness, dizziness, and itching. In clinical testing, those effects showed up at similar rates for both medications. One notable exception is constipation. In a controlled trial comparing the two for fracture pain, 21% of patients taking hydrocodone developed constipation, while none of the oxycodone patients did. That’s a meaningful gap if you’re already prone to digestive issues or taking other medications that slow your gut.
Both drugs carry the same serious risks that come with any opioid: slowed breathing (especially at higher doses or when combined with alcohol or sedatives), physical dependence with regular use, and the potential for addiction.
How Your Body Processes Each Drug
Your liver breaks down both oxycodone and hydrocodone using the same family of enzymes, but the details differ in ways that affect drug interactions.
Oxycodone is primarily processed by one liver enzyme pathway (responsible for roughly 45 to 50% of the dose) into a mostly inactive byproduct. A second pathway converts about 10 to 19% of each dose into oxymorphone, a metabolite that’s actually a more potent painkiller than oxycodone itself. Hydrocodone follows a parallel route, getting converted into hydromorphone through a similar enzyme.
This matters because other medications can speed up or slow down these enzymes. Certain antifungal drugs, some antibiotics, and HIV medications can block the main enzyme that clears oxycodone, causing it to build up in your system and potentially intensifying side effects, including dangerously slowed breathing. Some antidepressants, particularly SSRIs like paroxetine, can block the enzyme that creates the active metabolite, which may reduce how well oxycodone controls pain.
Hydrocodone is processed through the same enzyme pathways and faces similar interactions, but oxycodone’s reliance on multiple competing pathways makes its interaction profile somewhat more complex. If you take several other medications, your prescriber may factor this into the choice between the two drugs.
The Acetaminophen Factor
Because both Percocet and Vicodin contain acetaminophen, the total daily dose of acetaminophen across everything you take is a critical safety consideration. The FDA sets the maximum at 4,000 mg per day for adults from all sources combined. That ceiling includes any over-the-counter cold medicines, headache pills, or sleep aids that also contain acetaminophen.
Exceeding that limit can cause serious liver damage, sometimes severe enough to require a transplant. If you’re prescribed either of these medications and you also use Tylenol or similar products for other aches, add up the milligrams. For example, taking a combination tablet with 325 mg of acetaminophen every four hours gives you 1,950 mg from the prescription alone over 24 hours, leaving limited room for additional acetaminophen from other sources.
How Prescribers Choose Between Them
In practice, the choice often comes down to a few factors. Oxycodone’s higher potency per milligram makes Percocet a common pick for moderate-to-severe pain, such as after surgery or a significant injury. Vicodin is frequently prescribed for slightly less intense pain or as a first-line option before stepping up to something stronger.
Your other medications also influence the decision. Someone taking drugs that interact heavily with the enzymes that process oxycodone may do better on hydrocodone, or vice versa. A history of constipation might tip the scale toward oxycodone, given the difference seen in clinical trials. And because both carry identical addiction and dependence risks, neither is considered “safer” than the other from a regulatory standpoint.
Both are meant for short-term use. If your pain persists beyond the expected recovery window, your prescriber will typically reassess rather than simply continue refilling either medication.