An occasional drink with a correctly dosed Tylenol (acetaminophen) is usually fine for most people, but the combination strains the liver — so stay within dosing limits, and if you drink heavily or daily, do not take it without asking your doctor or pharmacist.
Both alcohol and acetaminophen are processed by the liver, and the concern is liver injury rather than an immediate "don't-mix" reaction. The NHS says you can eat and drink normally, including alcohol, while taking paracetamol (acetaminophen). However, the FDA-mandated Tylenol "Liver warning" and MedlinePlus both single out heavier drinking: regular heavy alcohol use raises the risk of severe, even fatal, liver damage from acetaminophen, which is why the US label warns specifically about people who have 3 or more alcoholic drinks every day. NHS also states paracetamol may not be suitable for people who are dependent on alcohol or binge drink.
Stay within the dose on the label: for adults the maximum is 4,000 mg of acetaminophen in 24 hours from ALL sources, and never take two products containing acetaminophen at once (it hides in many cold, flu, and prescription painkiller combos). Per MedlinePlus and the FDA label, do not take acetaminophen if you have 3 or more alcoholic drinks every day — talk to your doctor first. Avoid it entirely, or get medical advice, if you have liver disease, are alcohol-dependent, or binge drink. Do not use it for more than 3 days for fever or 10 days for pain without seeing a clinician. Seek urgent medical help if you notice yellowing of the skin or eyes, dark urine, pale stools, upper-belly pain, sweating, extreme tiredness, flu-like symptoms, or unusual bleeding or bruising — these can signal liver damage, and acetaminophen overdose can be life-threatening even before symptoms appear. This is general information, not medical advice; check with a pharmacist or doctor about your situation.
This is general reference, not medical advice, and not a guarantee of safety. Interactions depend on your doses, health conditions, and other medicines. Always confirm with your pharmacist or doctor before combining products, and follow the dosing on each label.