Penicillin is a prescription-only medication in the United States, so the only way to get it is through a healthcare provider. You cannot buy it over the counter at a pharmacy. The good news is that penicillin is one of the most affordable antibiotics available, and there are several straightforward ways to get a prescription.
Why You Need a Prescription
Penicillin requires a prescription for two important reasons. First, a provider needs to determine whether your infection is actually bacterial. Many common illnesses that feel like they need antibiotics, like colds, most sore throats, and coughs from respiratory infections, are caused by viruses. Antibiotics do nothing for viral infections, and taking them unnecessarily fuels antibiotic resistance, which the World Health Organization considers one of the biggest threats to global public health.
Second, even when an infection is bacterial, penicillin only works against certain types of bacteria. Resistance is a growing problem. Among strains of the bacteria that cause pneumonia, for example, susceptibility to penicillin ranges from about 80% down to as low as 52% depending on the strain. A provider needs to match the right antibiotic to the right infection, sometimes using lab tests to confirm what you’re dealing with.
There’s also a safety concern. Roughly 10% of U.S. patients report a penicillin allergy, though fewer than 1% turn out to be truly allergic when tested. A provider can evaluate your allergy history before prescribing and choose an alternative if needed.
Visiting a Doctor or Urgent Care
The most common route to a penicillin prescription is an in-person visit. For something like strep throat, which is one of the most frequent reasons penicillin is prescribed, your provider will typically do a rapid strep test or throat culture before writing a prescription. This matters because about 70% of sore throats are viral, and the symptoms can look identical. A quick swab takes minutes and gives you a clear answer.
Urgent care clinics are a practical option if you can’t get a same-day appointment with your primary care doctor. They can run the same tests and prescribe penicillin on the spot. For ear infections, skin infections, or dental infections, the process is similar: an exam, sometimes a test, and a prescription if antibiotics are warranted.
Getting a Prescription Through Telehealth
Telehealth visits can sometimes lead to an antibiotic prescription, but there are limits. The CDC recommends that when a physical exam or lab test is needed to make a proper diagnosis, telemedicine services should coordinate with in-person clinics or labs to complete that step. Strep throat, ear infections, and urinary tract infections all fall into this category.
In practice, this means a telehealth provider may be able to prescribe penicillin for a condition where the diagnosis is clear from your symptoms and medical history, but they’ll often direct you to an in-person visit or a lab for testing first. If a virtual visit can’t meet your needs, the clinician should refer you to an in-person care site. Telehealth works best as a starting point when you’re unsure whether you need to be seen or want guidance on next steps.
What Penicillin Is Prescribed For
Penicillin comes in several forms, and the one you receive depends on your infection. The oral tablet version (penicillin V) is used for mild to moderate infections: strep throat, scarlet fever, certain skin infections, and gum infections. This is the form most people encounter. A typical course for strep throat is either 250 mg four times daily or 500 mg twice daily for 10 days.
The injectable version (penicillin G) is reserved for more serious infections like meningitis, syphilis, and certain heart valve infections. You’d receive this in a hospital or clinical setting. A long-acting injectable form (benzathine penicillin) is used for syphilis treatment and to prevent rheumatic fever, often as a single shot or a series of shots.
Cost Without Insurance
Penicillin is one of the cheapest antibiotics you can fill. Without insurance, a standard 10-day course of oral penicillin costs roughly $18 at most pharmacies. That’s for either 20 tablets of 500 mg or 40 tablets of 250 mg. Discount programs like GoodRx can sometimes bring the price down further. With insurance, your copay is often less than that.
If You Have a Penicillin Allergy
If you’ve been told you’re allergic to penicillin, it’s worth knowing that the vast majority of people with that label aren’t actually allergic. Allergies can fade over time, and many reactions people remember from childhood were side effects rather than true allergic responses. Allergy testing, usually a simple skin test, can clarify whether you can safely take penicillin. This is especially useful because penicillin-allergic patients often end up on broader-spectrum antibiotics that are more expensive and more likely to cause side effects or drive resistance.
For people with a confirmed allergy, providers typically prescribe alternatives from different antibiotic classes. The specific choice depends on the infection being treated and how severe the allergic reaction was in the past.
What Won’t Work
You may come across suggestions to use fish antibiotics or veterinary penicillin as a workaround. These products are not manufactured under the same safety standards as human medications, may contain different inactive ingredients, and carry real risks. Similarly, purchasing antibiotics from overseas pharmacies or without a prescription online is illegal in the U.S. and dangerous. You have no way to verify the drug’s quality, dosage, or even whether it contains what the label claims.
Taking leftover antibiotics from a previous prescription is also risky. The leftover supply is rarely the right drug, dose, or duration for a new infection, and partial courses of antibiotics are a direct driver of resistance.