Percocet is stronger than Norco on a milligram-for-milligram basis. The opioid in Percocet (oxycodone) is about 1.5 times more potent than the opioid in Norco (hydrocodone), meaning you need less oxycodone to achieve the same level of pain relief. In practice, though, the difference is more nuanced than a simple “stronger vs. weaker” ranking.
How the Two Drugs Compare by Potency
The standard way to compare opioid strength is through morphine milligram equivalents, which measure how much of each drug provides the same pain relief as a set dose of morphine. Using this system, 20 mg of oxycodone equals 30 mg of oral morphine, while hydrocodone matches morphine roughly 1:1, meaning 30 mg of hydrocodone equals 30 mg of oral morphine. That makes oxycodone about 50% more potent per milligram.
This doesn’t mean Percocet will always feel 50% stronger than Norco when you take it, because the two medications come in different tablet strengths. Percocet is available in 2.5 mg, 5 mg, 7.5 mg, and 10 mg oxycodone tablets, each paired with 325 mg of acetaminophen. Norco contains 5 mg of hydrocodone with 325 mg of acetaminophen (other hydrocodone products come in 7.5 mg and 10 mg strengths). A 5 mg Percocet tablet is meaningfully stronger than a 5 mg Norco tablet, but a 10 mg Norco could deliver similar relief to a 5 mg or 7.5 mg Percocet. The dose your provider chooses matters as much as which drug they pick.
What Clinical Trials Actually Show
A double-blind randomized trial compared 5 mg oxycodone with acetaminophen against 5 mg hydrocodone with acetaminophen in emergency department patients with acute fractures. At 30 minutes, both groups experienced significant pain reduction. The oxycodone group’s pain scores dropped by an average of 3.7 points, while the hydrocodone group dropped by 2.5 points. By 60 minutes, the gap was similar: 4.4 points versus 3.0 points. Statistically, though, the difference between the two groups was not significant at either time point.
The researchers concluded that oxycodone and hydrocodone have “similarly potent analgesic effects in the first hour of treatment” for acute fracture pain. So while oxycodone has a higher potency on paper, patients in controlled settings reported comparable relief at the same dose. Individual biology, the type of pain, and how your body metabolizes each drug all play a role in which one works better for you.
Side Effects: Small but Real Differences
In the same fracture trial, rates of nausea, vomiting, itching, and drowsiness were similar between the two drugs. The one notable exception was constipation: 21% of patients taking hydrocodone developed constipation, compared to 0% of patients on oxycodone. That’s a meaningful gap if you’re already prone to digestive issues or recovering from surgery where straining could be a problem.
Both drugs share the core side effects common to all opioids: drowsiness, dizziness, nausea, and slowed breathing at higher doses. Neither is meaningfully “safer” than the other in terms of serious risks. Both carry the same potential for dependence and misuse, and both are classified as Schedule II controlled substances by the DEA, the most restrictive category for drugs that have accepted medical use.
The Acetaminophen Factor
Both Percocet and Norco contain acetaminophen (the active ingredient in Tylenol), which boosts pain relief but adds a safety ceiling. The FDA sets the maximum recommended daily dose of acetaminophen at 4,000 mg across all sources, including over-the-counter products. Each Percocet and Norco tablet contains 325 mg, so taking six tablets a day puts you at nearly 2,000 mg from the prescription alone.
This becomes a real concern if you’re also taking cold medicine, sleep aids, or headache remedies that contain acetaminophen. Exceeding the daily limit can cause liver damage, sometimes severe. If your pain requires higher or more frequent opioid dosing, your provider may switch you to a formulation without acetaminophen rather than simply increasing the number of combination tablets.
When One Might Be Chosen Over the Other
There’s no universal rule that Percocet is “for worse pain” and Norco is “for mild pain.” Providers choose between them based on several factors: how you’ve responded to opioids before, your risk profile, the type of pain you’re dealing with, and sometimes practical considerations like insurance coverage or what’s available at the pharmacy.
For dental pain specifically, the evidence suggests that anti-inflammatory medications like ibuprofen often outperform opioid and acetaminophen combinations. A systematic review found that NSAIDs were more effective than oxycodone-acetaminophen combinations for postoperative dental pain, largely because dental pain is driven by inflammation, which opioids don’t directly address. If you’ve been prescribed Percocet or Norco after a dental procedure and it isn’t helping much, that’s worth mentioning to your dentist.
For post-surgical or trauma-related pain, both drugs are commonly prescribed. Percocet’s higher potency per milligram can make it a better fit when stronger relief is needed without increasing the number of tablets (and therefore the acetaminophen load). Norco may be preferred when a slightly less potent option is appropriate, or when a patient has responded well to hydrocodone in the past.
The Bottom Line on Strength
Oxycodone, the opioid in Percocet, is pharmacologically stronger than hydrocodone, the opioid in Norco, by about 50% on a milligram-for-milligram basis. In real-world use, the two drugs provide similar pain relief at the doses typically prescribed, and the choice between them depends on more than raw potency. How your body processes each drug, the type of pain you’re experiencing, and the side effects you’re most sensitive to all shape which one will actually work better for you.