Quick answer for how long does Amoxicillin stay in your system? Amoxicillin will stay in your body for 24-48 hours.

Amoxicillin is an antibiotic with a half life of roughly one hour. Within 60 minutes of taking the medicine, the amount of Amoxicillin ingested will be reduced by one half. After 12 hours, the majority of medicine, about 95%, will be metabolized and expelled from the body in urine. Traces of Amoxicillin will appear in blood and urine for 24-48 hours depending on the quantity taken. Lingering side effects from Amoxicillin such as constant urination or diarrhea may appear for an additional 24 hours after the drug has been ejected from the body.
Additional Drug Information:
Amoxicillin is a semi-synthetic form of penicillin commonly used to treat bacterial infections. The common form of drug intake is through oral ingestion (swallowing).
It is one of the most commonly prescribed antibiotics for pediatrics and children. Amoxicillin is available in liquid form, chewable capsules, and oral tablets.
Side Effects of Amoxicillin include vomiting, disorientation, nausea, diarrhea, and easy fatigue.
A small percentage of people, 3 to 5%, develop a non-allergic skin rash up to 72 hours after ingestion of the drug. The “Amoxicillin rash” is non-fatal, simply incredibly itchy. If the rash occurs, stop taking the drug immediately and it should disappear within additional week. The rash is a NON allergic reaction. Should a true allergy reaction occur, seek immediate medical attention.