How Long Does Amoxicillin Last?

James Davis

When you have ended the course of the treatment but the remedy is still left, you may wonder what to do with it. For instance, such a situation may happen with Amoxicillin, a commonly utilized antibiotic for the cure of various infections. How long does it last? Will it be suitable for further use or is it dangerous? The answer to this and other questions are given further.

What is Amoxicillin

This remedy belongs to the group of semisynthetic beta-lactam antibiotics. This penicillin derivative is able to kill different microorganisms and treat infections that they cause.

The drug is backed by science, thoroughly studied and suitable for both adults and children. It rarely causes side effects. Thus, it’s widely used in modern clinical practice and is often prescribed by doctors.

Common uses

As a prescription medication, one can purchase generic Amoxicillin or brand Amoxil. FDA approves both forms for the following bacterial infections:

  • ears, nose and throat;
  • urinary tract;
  • skin;
  • lower respiratory tract;
  • sexually transmitted diseases like gonorrhea.

The remedy can be utilized by all age categories but with appropriate doses. The latter are decided by the specialist.

How it works

All so-called beta-lactam antibiotics hinder the formation of bacterial cell walls. Due to this, bacteria cannot grow and live normally. Subsequently, they die and are eliminated from the body and the disease ceases.

How Long Does Amoxicillin Last

Several dosage forms of this remedy are available. They differ in the terms of utilization, namely:

  • tablets and capsules have a shelf life equal to a period from 1 to 3 years. On average, it is recommended to store them in a shadowy dry place up to the expiration date;
  • suspension is prepared by the pharmacist directly before the purchase of the sterile powder. It must be used for 14 days after the preparation. It can be stored in the fridge or in a shadowy dry place.

Always check the date and do not use the remedy after it. For Amoxicillin, as for any other remedy, it must be clearly designated on the packaging. Therefore, check this information during the purchase and consult a pharmacist if you have any doubts.

Expiry Date vs. Shelf Life

The expiry date of any medicine is determined by its manufacturer. Before this time, the remedy must stay effective and safe and not change during storage. As for the shelf life, this period may be a bit longer and does not guarantee safety.

Anyway, it is not recommended to utilize medicines after both these terms have ended. Even when the tablet looks like normal, you will never know what has happened inside it. Thus, the remedy might lose its efficiency, change chemically, etc.

This will lead to the absence of the desired effect, on the one hand. On the other hand, unpredicted side effects may occur and create additional problems for the health of the patient. That is why follow the recommendations of the manufacturer and pharmacist and do not use medicine after the expiration date.

How Long Amoxicillin Stays in Your System

The average dose of this remedy stays inside the body for the period from 8 to 12 hours. During this time, the drug is still effective and may also provide certain side effects.

Thus, when you have taken the last dose, you should be aware that the effect lasts up to 12 hours more.

How long does amoxicillin last in children?

In children, these numbers are nearly the same as for adults in general. The exact time depends on the prescribed dose but at least 8 hours of action are observed. During this time, the active ingredient stays in the body.

Side Effects of Amoxicillin

This remedy is not associated with severe side effects and may cause such minor issues as nausea and vomiting, diarrhea, headaches and changes in taste.

The most severe probable reaction is allergy. There are many people prone to it, so it’s better to check the reaction before the utilization. Amoxicillin may cause skin rash and more pronounced reactions, including difficulties in breathing. Therefore, it is not utilized for patients with allergies to beta-lactams.

How Long Does Amoxicillin Side Effects Last?

Minor side effects usually last for no more than 12 hours. During this time, the active ingredient leaves the body and any adverse reactions stop.

If they persist, do not hesitate to contact your doctor to take further action and get an adequate help.

Short-course Amoxicillin Treatment

This remedy is rarely prescribed for quite a long treatment. The standard course lasts 5 days and may be considered as short. Still, it is highly important to follow the scheme and not stop it earlier.

Even if you feel better, harmful microorganisms may still be alive. In case you stop the treatment, they may become active and the disease will return. In addition, bacteria can gain resistance. This means they will not respond to the usual dose of antibiotic and it’ll be necessary to choose another one.

That is why Amoxicillin, as well as other antibiotics, is not an OTC option. The specialist must prescribe it and control the process of treatment.

Long-course Amoxicillin Treatment

As for longer courses, they are considered such when they last for more than 7 days. This is quite a rare case with this remedy. However, it depends on the situation and individual characteristics of the patient. Anyway, follow your doctor’s advice.


Altogether, Amoxicillin is a remedy with a powerful action and good tolerability. It is widely used in modern clinical practice due to the low occurrence of side effects and the perfect ability to treat patients of all ages.

Different dosage forms of this medicine have their own shelf life. Thus, follow these numbers and do not use them after the expiry date. It is easy and safe to get a new prescription and cure the diseases with a proper antibiotic.


Allergic reaction to amoxicillin how long does it last?

In case, it is a minor skin rash, it should not last longer than a few days. However, if you experience an allergy, visit a doctor to replace the antibiotic and get a cure for this reaction.

What happens if I take expired amoxicillin?

This may lead to unexpected side effects and such a remedy will not cure the disease properly. That is why such a remedy must always be of a proper quality.

How long are antibiotics good for after the expiration date?

There is no scientific evidence on this issue. They may be good or spoiled as well. Therefore, never utilize them after the expiration date.