When deciding between Tylenol (acetaminophen) and Advil (ibuprofen) for fever reduction, it's important to consider several factors, such as effectiveness, safety, and potential side effects.

Both Tylenol and Advil are effective at reducing fever, but they work in different ways. Tylenol works by affecting the body's temperature control system in the hypothalamus, while Advil is a nonsteroidal anti-inflammatory drug (NSAID) that reduces fever by inhibiting the production of prostaglandins, which are hormone-like substances that cause inflammation and fever [1].

In terms of safety, both medications are generally safe when used as directed. However, it's important to note that Tylenol can cause liver damage if taken in excessive amounts, while Advil can cause stomach ulcers and kidney problems with long-term use or in high doses [2].

When it comes to side effects, both medications can cause stomach upset, but Advil is more likely to cause stomach ulcers and bleeding, especially in older adults or those taking blood-thinning medications [3]. Tylenol is generally considered safer for children and pregnant women, but it's important to consult with a healthcare provider before taking any medication during pregnancy [4].

In terms of cost, Tylenol is generally less expensive than Advil, but the cost can vary depending on the dosage and formulation [5].

In summary, both Tylenol and Advil are effective at reducing fever, but they have different mechanisms of action and potential side effects. When choosing between the two, it's important to consider factors such as safety, cost, and individual health needs.

Sources:

1. Mayo Clinic. (2021). Fever: First aid. <https://www.mayoclinic.org/first-aid/first-aid-fever/basics/art-20056681>.
2. National Institute of Diabetes and Digestive and Kidney Diseases. (2017). Nonsteroidal Anti-inflammatory Drugs (NSAIDs). <https://www.niddk.nih.gov/health-information/medical-reference/nonsteroidal-anti-inflammatory-drugs-nsaids>.
3. U.S. Food and Drug Administration. (2016). FDA strengthens warning that non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) can cause heart attacks or strokes. <https://www.fda.gov/drugs/drug-safety-and-availability/fda-strengthens-warning-non-aspirin-nonsteroidal-anti-inflammatory-drugs-nsaids-can-cause>.
4. American Academy of Pediatrics. (2015). Use of Acetaminophen and Ibuprofen in Children. <https://pediatrics.aappublications.org/content/136/6/e1652>.
5. DrugPatentWatch. (n.d.). Acetaminophen vs Ibuprofen. <https://www.drugpatentwatch.com/drug-comparison/acetaminophen-vs-ibuprofen>.