Percocet is stronger than Vicodin. Milligram for milligram, the opioid in Percocet (oxycodone) is about 1.5 times more potent than the opioid in Vicodin (hydrocodone). That said, when both drugs are prescribed at their standard starting doses, the actual pain relief patients experience is surprisingly similar.
How Potency Is Measured
Doctors compare opioid strength using a standard scale called morphine milligram equivalents, or MME. Every opioid gets a conversion factor that reflects how it stacks up against morphine. Hydrocodone, the active opioid in Vicodin, has a conversion factor of 1, meaning it’s roughly equal to morphine. Oxycodone, the opioid in Percocet, has a conversion factor of 1.5.
In practical terms, 20 mg of hydrocodone per day equals 20 MME, while 20 mg of oxycodone per day equals 30 MME. So if you took the same number of milligrams of each drug, the Percocet dose would hit harder. This is why doctors typically prescribe oxycodone at lower milligram amounts to achieve similar effects.
What the Research Shows About Pain Relief
A double-blind clinical trial compared 5 mg of oxycodone to 5 mg of hydrocodone (both combined with acetaminophen) in emergency department patients with acute fractures. At 30 minutes, the oxycodone group’s pain dropped by an average of 3.7 points on a 10-point scale, while the hydrocodone group dropped by 2.5 points. At 60 minutes, the gap was similar: 4.4 points versus 3.0 points.
Despite those raw numbers, the statistical analysis found no meaningful difference between the two drugs at either time point. The researchers concluded that oxycodone and hydrocodone “have similarly potent analgesic effects in the first hour of treatment.” This makes sense given the MME difference. At equal 5 mg doses, oxycodone is technically delivering more opioid power, but the clinical result for patients is nearly indistinguishable.
Available Strengths
Vicodin comes in tablets containing 2.5, 5, 7.5, or 10 mg of hydrocodone, each paired with 300 or 325 mg of acetaminophen. Percocet follows a similar range, with oxycodone doses of 2.5, 5, 7.5, or 10 mg combined with 325 mg of acetaminophen. Because oxycodone is inherently stronger per milligram, a Percocet 5 mg tablet delivers more opioid effect than a Vicodin 5 mg tablet, even though the number on the label looks the same.
Both drugs contain acetaminophen, which adds its own pain-relieving effect on top of the opioid. The FDA caps total acetaminophen intake at 4,000 mg per day across all medications, including over-the-counter products like Tylenol. This limit is important because exceeding it can cause serious liver damage, and it can constrain how many tablets you safely take in a day.
Side Effects
The two drugs share a nearly identical side effect profile. In the fracture study, rates of nausea, vomiting, itching, and drowsiness were statistically the same between the oxycodone and hydrocodone groups. The one notable exception was constipation: 21% of patients taking hydrocodone developed constipation, compared to 0% of those on oxycodone. That’s a meaningful gap, though it comes from a relatively small study of 67 patients and may not hold true for everyone.
Both medications carry the standard opioid side effects you’d expect: drowsiness, dizziness, nausea, and slowed breathing at higher doses. Neither drug has a clearly “easier” side effect profile overall.
How Long Each Drug Works
Immediate-release hydrocodone reaches peak blood levels within about one hour and has a half-life of roughly four hours, meaning it’s largely cleared from your system after about eight hours. Oxycodone follows a similar timeline, with onset within 15 to 30 minutes and a comparable duration. In practice, both drugs are typically taken every four to six hours for acute pain, so neither one lasts meaningfully longer than the other.
Abuse Potential and Scheduling
Both Vicodin and Percocet are classified as Schedule II controlled substances by the DEA, the category reserved for drugs with a high potential for abuse that can lead to severe physical or psychological dependence. This wasn’t always the case for Vicodin. Hydrocodone combination products were reclassified from Schedule III to Schedule II in 2014, reflecting growing concern about their role in the opioid crisis. Today, prescriptions for both medications come with the same regulatory restrictions: no refills, no phone-in prescriptions in most states, and a new prescription required each time.
Because oxycodone is more potent per milligram, some research suggests it may produce slightly stronger euphoric effects at equivalent doses, which could translate to higher abuse liability. But at the prescribed doses most patients actually receive, the practical difference in addiction risk between the two drugs is not well established.
Why Doctors Choose One Over the Other
The choice between Vicodin and Percocet often comes down to a prescriber’s preference, the specific type of pain being treated, and how a patient has responded to opioids in the past. For moderate pain after a dental procedure, hydrocodone might be the first choice simply because it’s slightly less potent and provides adequate relief. For more intense post-surgical pain, oxycodone’s extra potency per milligram can be useful. Neither drug is categorically “better.” A large study comparing oxycodone to a milder opioid after surgical fracture repair found the difference in daily pain scores was less than half a point on a 10-point scale, not enough to be clinically meaningful.
If you’ve been prescribed one and are wondering whether the other would work better for you, the key takeaway is that at typical prescribed doses, the pain relief is very similar. The higher potency of Percocet doesn’t automatically make it more effective for your situation, because your doctor has already accounted for that difference when choosing the dose.