Advil is a brand name for the drug ibuprofen, which is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain, reduce fever, and decrease inflammation [1]. While Advil is generally safe for teenagers, there are some medical conditions that may make it unsafe. For example, individuals with a history of stomach ulcers, gastrointestinal bleeding, or kidney disease should avoid taking Advil [3]. Additionally, individuals with a rare but serious condition called Reyes syndrome should not take Advil [2]. Reyes syndrome is a rare condition that can occur in children and teenagers who are recovering from a viral infection, and it can cause severe liver and brain damage [2].

Therefore, it is important for teenagers with medical conditions to consult with their healthcare provider before taking Advil or any other medication. Healthcare providers can evaluate a teenager's medical history and current health status to determine if Advil is safe for them to take, and if so, what dosage is appropriate [3].

In summary, Advil is generally safe for teenagers, but there are certain medical conditions, such as Reyes syndrome, stomach ulcers, gastrointestinal bleeding, and kidney disease, that may make it unsafe. It is important for teenagers with medical conditions to consult with their healthcare provider before taking Advil or any other medication [1][2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ADVIL
[2] https://www.mayoclinic.org/diseases-conditions/reyes-syndrome/symptoms-causes/syc-20377255
[3] https://kidshealth.org/en/parents/ibuprofen.html