Tylenol 3 and Tylenol 4 contain the same two active ingredients, acetaminophen and codeine, in the same type of tablet. The only difference is how much codeine is in each one. Tylenol 3 has 30 milligrams of codeine per tablet, while Tylenol 4 has 60 milligrams. Both contain 300 milligrams of acetaminophen. That doubled codeine dose is a meaningful clinical distinction, affecting pain relief, side effects, and the risk of serious complications.
What Is in Each Tablet
Both Tylenol 3 and Tylenol 4 are brand-name versions of combination acetaminophen-codeine tablets. The acetaminophen component is the same over-the-counter pain reliever found in regular Tylenol, dosed at 300 mg in both formulations. The codeine is an opioid that adds stronger pain relief on top of what acetaminophen alone can provide. The numbering system reflects a scale of codeine strength: Tylenol 2 contains 15 mg of codeine, Tylenol 3 bumps it to 30 mg, and Tylenol 4 doubles that to 60 mg. In practice, Tylenol 2 is rarely prescribed in the United States, so most people encounter only the 3 and 4 versions.
Because both products share the same acetaminophen dose, the practical question when comparing them is always about the codeine. Doubling the codeine from 30 mg to 60 mg does not simply double the pain relief in a neat, linear way. The relationship between codeine dose and effect depends on your body’s ability to convert codeine into its active form, how tolerant you are to opioids, and how sensitive you are to side effects. That variability is why both strengths exist rather than just one.
How Codeine Actually Works in the Body
Codeine itself is not especially potent as a painkiller. It functions mostly as a prodrug, meaning your liver has to convert it into morphine before it does much of anything for pain. An enzyme called CYP2D6 handles that conversion.1National Center for Biotechnology Information. Codeine Therapy and CYP2D6 Genotype The morphine produced by this process is what actually binds to opioid receptors and provides the analgesic effect. This is an important detail because it means codeine’s effectiveness is not purely about the dose on the label. It is also about how well your particular version of that enzyme works, a topic covered in more detail below.
Acetaminophen, meanwhile, works through a completely different pathway. It reduces pain signals in the central nervous system and lowers fever. The two drugs target pain through separate mechanisms, which is why combining them tends to work better than either drug alone at equivalent doses. The acetaminophen handles milder background pain, while the codeine-derived morphine tackles sharper or more persistent pain.
When Each Strength Gets Prescribed
Doctors typically start with Tylenol 3 for moderate pain that has not responded well to over-the-counter options. Research supports the acetaminophen-codeine combination as effective for moderate to severe pain across a range of conditions, including post-surgical pain, headache, bone and joint pain, and pain from injuries.2European Review for Medical and Pharmacological Sciences. Safety and efficacy of the combination acetaminophen-codeine in the treatment of pain of different origin In many cases, 30 mg of codeine is enough. Tylenol 3 is the workhorse of the lineup and accounts for the vast majority of acetaminophen-codeine prescriptions.
Tylenol 4 tends to be reserved for situations where 30 mg of codeine is not cutting it, or where the patient has some opioid tolerance from prior use. A person recovering from a more involved surgical procedure, for example, or someone with chronic pain that has not responded to lower doses, might be moved up to the 60 mg formulation. Prescribers are generally cautious about jumping straight to Tylenol 4 in opioid-naive patients because the higher codeine dose carries a proportionally higher risk of side effects.
It is worth noting that the difference in pain relief between 30 mg and 60 mg of codeine is real but not dramatic for most people. Codeine is a relatively weak opioid compared to drugs like oxycodone or hydrocodone, and there is a ceiling to how much pain relief it can deliver regardless of dose. If Tylenol 4 still is not providing adequate pain control, the next step is usually switching to a different, stronger opioid rather than continuing to increase the codeine dose.
Side Effects Scale with the Codeine Dose
The side effect profile for both Tylenol 3 and Tylenol 4 is driven primarily by the codeine component, and it follows a dose-dependent pattern. The most common complaint is constipation, which affects a large proportion of people taking codeine at any dose and does not tend to improve with continued use. Nausea and vomiting are also common, though these symptoms usually fade after the first days to weeks of regular use.3NCBI Bookshelf. Codeine Other possible effects include itching, urinary retention, blurred vision, weakness, and abdominal cramps.
Because Tylenol 4 delivers twice the codeine, the likelihood and severity of these side effects go up. Drowsiness and sedation are more pronounced at 60 mg. Respiratory depression, the most dangerous opioid side effect, is also more of a concern at higher doses. This does not mean Tylenol 3 is free of respiratory risk, but the margin of safety is wider at 30 mg than at 60 mg, particularly for people who are older, have lung conditions, or are taking other sedating medications.
The acetaminophen side of the equation carries its own risk, though it is the same for both products. Taking more than 4,000 mg of acetaminophen in a day can cause serious liver damage, and the threshold is lower for people who drink alcohol regularly. Because each tablet contains 300 mg of acetaminophen, someone taking the maximum prescribed dose of either Tylenol 3 or Tylenol 4 (typically two tablets every four to six hours) can approach that daily ceiling quickly. Adding any other acetaminophen-containing product on top of the prescription, even something as seemingly harmless as cold medicine, can push you over the line.
Genetic Differences That Change How Either Product Works
The CYP2D6 enzyme that converts codeine into morphine does not work the same way in everyone. People fall along a spectrum of metabolizer types based on which version of the CYP2D6 gene they carry. Most people are “normal” or “extensive” metabolizers and convert codeine at a predictable rate. But roughly 5 to 10 percent of people of European descent, and a smaller fraction of other populations, are “poor metabolizers” whose CYP2D6 enzyme barely works. For these individuals, codeine provides almost no pain relief at any dose because very little morphine gets produced. Tylenol 3 and Tylenol 4 would feel about the same to a poor metabolizer, which is to say, not very effective.
On the opposite end of the spectrum are “ultra-rapid metabolizers,” who carry extra-active copies of the gene and convert codeine into morphine much faster and in greater quantities than normal. For these individuals, even a standard 30 mg dose of codeine can produce dangerously high morphine levels.1National Center for Biotechnology Information. Codeine Therapy and CYP2D6 Genotype A 60 mg dose in an ultra-rapid metabolizer amplifies that danger further. This genetic variability is one reason some people report that codeine “doesn’t work” for them while others find even low doses overwhelming. It is not about pain tolerance or toughness. It is about enzyme function.
Pharmacogenomic testing can identify your CYP2D6 metabolizer status before you ever take codeine, but in practice this testing is not routinely ordered. Most people discover their metabolizer status indirectly: the codeine either works, does nothing, or hits them like a truck. If you have had an unusually strong or unusually weak reaction to codeine in the past, that experience is a useful data point to share with your prescriber before filling either a Tylenol 3 or Tylenol 4 prescription.
FDA Restrictions on Codeine in Children
The FDA has placed its strongest warning, a Boxed Warning, on codeine-containing products regarding use in children. The trigger was a series of cases in which children who were ultra-rapid metabolizers of codeine died or experienced life-threatening respiratory depression after receiving codeine for pain following tonsillectomy or adenoidectomy surgeries.4U.S. Food and Drug Administration. Safety review update of codeine use in children; new Boxed Warning and Contraindication on use after tonsillectomy and/or adenoidectomy In these children, the inherited ultra-rapid metabolizer trait caused their livers to produce fatal amounts of morphine from what were intended to be normal codeine doses.
Codeine is now contraindicated for post-tonsillectomy and post-adenoidectomy pain in children under 12. Many pediatric guidelines have gone further and recommend avoiding codeine in children altogether, regardless of the type of surgery or the indication. This applies equally to Tylenol 3 and Tylenol 4. If your child is prescribed either product, the FDA’s warnings are worth discussing with the prescriber, particularly if the child has not been tested for CYP2D6 status and has no track record with codeine.
Legal Scheduling and What It Means for Prescriptions
Both Tylenol 3 and Tylenol 4 are classified as Schedule III controlled substances under U.S. federal law. The DEA places products containing less than 90 milligrams of codeine per dosage unit into Schedule III.5Drug Enforcement Administration. Drug Scheduling Since Tylenol 3 has 30 mg and Tylenol 4 has 60 mg, both fall comfortably within this category. Schedule III means the drugs have a moderate to low potential for physical and psychological dependence, which places them below Schedule II drugs like oxycodone or hydrocodone but above Schedule IV drugs like benzodiazepines.
From a practical standpoint, Schedule III classification means you need a prescription, but your doctor can call or electronically transmit it to the pharmacy without the special triplicate paperwork required for Schedule II drugs in some states. Refills are allowed for up to six months from the original prescription date, up to five refills. This is a meaningful convenience difference compared to Schedule II opioids, which generally require a new prescription every time. Some states impose additional restrictions on top of the federal rules, so refill policies can vary depending on where you live.
The Schedule III classification is identical for both Tylenol 3 and Tylenol 4. Moving from one to the other does not involve any change in legal status, monitoring requirements, or prescription logistics. From a regulatory perspective, they are treated as the same category of drug.
Why Codeine Prescriptions Are Declining
Codeine-based products, including both Tylenol 3 and Tylenol 4, have been gradually falling out of favor in clinical practice. Several trends are converging. The recognition that CYP2D6 variability makes codeine unpredictable in a sizable minority of patients has pushed some prescribers toward drugs with more reliable metabolism. The FDA restrictions on pediatric use removed a large segment of the population from codeine eligibility. And the broader opioid crisis has made clinicians more cautious about prescribing any opioid when non-opioid alternatives exist.
For many of the conditions where Tylenol 3 or 4 would traditionally have been prescribed, studies have shown that combinations of over-the-counter medications like ibuprofen and acetaminophen taken together can match or approach the pain relief provided by acetaminophen with codeine, without the opioid-related risks. This has been particularly well studied in dental pain and post-surgical settings. As a result, some emergency departments and outpatient clinics have moved codeine combinations off their default prescribing lists in favor of these non-opioid regimens.
That said, codeine combinations remain widely available and continue to serve a role for patients who cannot tolerate NSAIDs like ibuprofen (due to stomach ulcers, kidney disease, or certain cardiovascular conditions) and who need something stronger than acetaminophen alone. The decline is a shift in first-line preference, not an abandonment of the drug. If you are prescribed Tylenol 3 or 4 today, it usually means your prescriber has considered the alternatives and determined that the codeine combination is the best fit for your specific situation.
Dependence and Withdrawal Potential
Codeine is an opioid, and all opioids carry the risk of physical dependence when taken regularly over time. Physical dependence is not the same thing as addiction, though the two are often conflated. Dependence means your body adapts to the presence of the drug, and stopping abruptly causes withdrawal symptoms: anxiety, sweating, muscle aches, diarrhea, and insomnia are common. Addiction involves compulsive drug-seeking behavior and continued use despite harm, and it develops in only a fraction of people who become physically dependent.
The risk of dependence scales with both dose and duration. Someone taking Tylenol 4 at 60 mg of codeine per tablet, especially multiple times a day for weeks, faces a higher dependence risk than someone taking Tylenol 3 at 30 mg for a few days after a dental procedure. Short courses of either product for acute pain, the most common prescribing scenario, carry a low dependence risk for most people. The concern increases when prescriptions stretch beyond two or three weeks, or when the medication is used to manage chronic rather than acute pain.
If you have been taking either Tylenol 3 or Tylenol 4 regularly for more than a couple of weeks, do not stop abruptly without talking to your prescriber. A tapered reduction in dose over several days can prevent or minimize withdrawal symptoms. This is a practical consideration regardless of which formulation you are on, though the higher codeine dose in Tylenol 4 makes a taper more important than it might be at the lower dose.