How long is amoxicillin good for in the fridge?

In this article:

• Proper storage
• How long does amoxicillin last in the fridge?
• Leftover amoxicillin
• Expired amoxicillin
• The bottom line

In this article

• Proper storage
• How long does amoxicillin last in the fridge?
• Leftover amoxicillin
• Expired amoxicillin
• The bottom line

Amoxicillin (brand names Amoxil, Amoxicillin, Sumox, and Trimox) is a generic penicillin antibiotic that the U.S. Food and Drug Administration (FDA) approves to treat a variety of bacterial infections of the ear, nose, throat, lower respiratory tract, skin, skin structures, and urinary tract. It can also be used to treat H. pylori infection in stomach or intestinal ulcers. Dentists may also prescribe amoxicillin off-label to treat a severe form of gum disease known as periodontitis. Medical experts state that reconstituted liquid amoxicillin is good for 14 days if stored in the refrigerator, while the drug’s shelf life is extended to 1 to 2 years in capsule or tablet form.

Proper storage: Maximizing amoxicillin’s effectiveness

You must store amoxicillin properly to ensure its quality, safety, and effectiveness. According to Michael Genovese, MD, a board-certified physician, attorney, and chief medical officer of Ascendant New York, the storage of amoxicillin depends on its dosage form (e.g., liquids, capsules, or chewable tablets).

Below are the recommendations for storing each type of amoxicillin medication, according to Dr. Genovese:

• Liquid amoxicillin: “Liquid amoxicillin, often given to children, must be stored in the refrigerator at temperatures between 35 F and 46 F after being mixed with water by a pharmacist,” Dr. Genovese explains. “Shaking the bottle well before each use is essential to distribute the active ingredients evenly. Freezing liquid amoxicillin can ruin its effectiveness and should be avoided.”
• Amoxicillin capsules and tablets: Dr. Genovese says that solid forms of amoxicillin, such as the capsules and chewable tablets, should be stored at room temperature, preferably between 68 F and 77 F. “These solid forms should be kept in a cool, dry place, away from direct sunlight, heat, and moisture,” he says. “Storing them in a bathroom cabinet is not ideal due to humidity exposure.”

“No matter the form, amoxicillin should always remain in its original packaging with a tightly closed lid and be kept out of reach of children,” Dr. Genovese says.

It’s crucial that amoxicillin isn’t stored in a warm environment. “While amoxicillin is usually stable for 14 days at room temperature, if it is exposed to prolonged temperatures above 77 F, the stability and effectiveness of the medication could be compromised,” says Jessica Iroanya, Pharm.D., BCMTMSI, an RPh Advisor at CVS Health. 

How long does amoxicillin last in the fridge?

Reconstitution is the process of adding a liquid to a powdered medication and dissolving the medicine to form a solution. This process is how reconstituted amoxicillin is created. 

According to Dr. Iroanya, amoxicillin is stable for 14 days in a refrigerator after being reconstituted. “Amoxicillin capsules and tablets do not require refrigeration and should last until expiration,” she says.

Once liquid amoxicillin goes beyond the 14-day mark, Dr. Genovese says it can lose some effectiveness. “After this period, the medication starts to lose potency, even if it looks or smells normal,” he explains. “It should not be used past this timeframe and must be appropriately discarded. Capsules and tablets, on the other hand, have a much longer shelf life, often ranging between 1 and 2 years when stored correctly at room temperature. Always refer to the expiration date printed on the label for accuracy, which indicates the last date the manufacturer guarantees its safety and efficacy.”

Depending on the form of medication, refrigeration is essential for maintaining its effectiveness and shelf life. According to a 2021 study, improper medication storage can be potentially harmful as the medication may degrade and cause unwanted side effects once digested.

Regarding liquid amoxicillin suspension, Dr. Genovese says that once mixed with water, it can remain effective for 7 to 14 days when stored in the refrigerator. In contrast, he says that the shelf life of amoxicillin tablets or capsules can last between 1 and 2 years when stored properly at room temperature.

Dr. Iroanya says that the expiration date of all forms of amoxicillin is determined through stability testing. “Stability testing is performed under controlled conditions to monitor for signs of microbial growth and degradation when determining expiration dates assigned to liquid formulations of amoxicillin,” she explains. “Stability testing monitors for signs of chemical changes and degradation under controlled conditions and helps influence the expiration date assigned to tablet and capsule formulations.”

Dr. Genovese adds that this stability testing helps manufacturers set the expiration dates. “For liquid amoxicillin, the expiration date reflects how long the medication remains effective after being mixed with water, which is why it has a shorter shelf life of 7 to 14 days,” he explains. “For capsules and tablets, expiration dates are based on long-term stability studies, which typically guarantee efficacy for 1 to 2 years if the medication is stored correctly. These expiration dates are not arbitrary—they represent the manufacturer’s assurance of the drug’s potency and safety up until that point.”

Even when properly stored in the fridge, liquid amoxicillin can go bad. “Liquid amoxicillin can degrade and become unusable even when stored in the refrigerator,” Dr. Genovese says. “If kept beyond its recommended usage window of 7 to 14 days, the medication begins to lose potency and may no longer effectively treat bacterial infections.”
Dr. Genovese lists the following as signs that liquid amoxicillin has gone bad:

• Change in color (it may appear darker or yellow)
• Unusual or sour smell
• Grainy or clumpy texture

In contrast, Dr. Genovese says that amoxicillin capsules and tablets are more stable than the liquid form of the penicillin antibiotic but can also degrade if exposed to moisture, heat, or light. “If there’s any doubt about the medication’s safety, consult a pharmacist or healthcare professional,” he says.

Can you save leftover amoxicillin for future use?

If you have leftover amoxicillin, it’s best to discard it to protect your health, Dr. Iroanya says. “Amoxicillin loses its potency over time, which could lead to antibiotic resistance if unused portions of it are later taken for a new infection,” she says.

Antibiotic resistance (AR), also known as antimicrobial resistance (AMR), develops when bacteria, fungi, viruses, or parasites no longer respond to antibiotics, making infections harder to treat. AR can develop from the misuse and abuse of antimicrobials, such as amoxicillin. This is why it’s so important to only take antibiotics when needed and to discard them after completing the prescription.

There are other downsides to taking leftover amoxicillin medication. “First, leftover antibiotics may not provide an entire treatment, which can lead to incomplete bacterial eradication,” Dr. Genovese says. “Second, not all infections require antibiotics, and self-diagnosing could delay proper treatment. Lastly, stored antibiotics may lose potency over time, especially if not stored correctly.”
Dr. Genovese recommends disposing of unused amoxicillin (or any prescription drug) through the FDA’s drug take-back program or by following your pharmacist’s disposal instructions. 

Is it okay to take expired amoxicillin?

So, what should you do when your amoxicillin expires? Dr. Iroanya advises against using it beyond the drug expiration date. “The medication loses potency over time, leading to ineffective or incomplete treatment,” she explains. “Furthermore, changes in the medication could occur due to improper storage, handling, and contamination, leading to safety concerns.”
Taking expired amoxicillin could also lead to unwanted side effects due to the chemical breakdown of the prescription medication, Dr. Genovese adds. 

The potential side effects of taking expired antibiotics include the following:

• Antibiotic resistance
• Nausea
• Vomiting
• Metabolic acidosis (a severe condition that develops when there’s too much acid in your body.

The bottom line

Amoxicillin is a penicillin antibiotic available in the form of capsules, tablets, and liquid solutions. According to medical experts, you can preserve the quality of amoxicillin by storing the liquid form in the refrigerator for up to 14 days and keeping capsules and tablets at room temperature for up to 2 years. If you have questions or concerns about amoxicillin or other antibiotics, please consult your healthcare provider or pharmacist for professional medical advice.