What it's used for
Cephalexin is an antibacterial drug used to treat respiratory tract, middle ear, skin, bone, and genitourinary tract infections caused by susceptible bacteria.
Source: U.S. FDA-approved prescribing information (openFDA).
Typical dosing
For adults, the usual dose is 250 mg every 6 hours or 500 mg every 12 hours, while pediatric dosing depends on the infection type and severity.
Dosing shown here is the general FDA-labeled range. Your prescribing clinician determines the exact dose, form, and schedule for you — this is not a substitute for medical advice.
Common side effects
See full FDA prescribing information for the complete adverse reaction profile.
Covered strengths on the Tab $0 list
Covered at $0 with an active Tab membership when filled at a participating pharmacy nationwide or through mail order. A licensed clinician must prescribe the medication.
Related medications
Other antibiotics & antivirals medications covered at $0 with an active Tab membership.
Cephalexin cost without insurance
Cash prices for Cephalexin without insurance vary widely by pharmacy, strength and quantity — the same prescription can cost very different amounts at two pharmacies in the same town. That is the problem a membership solves.
Cephalexin is on Tab's covered $0 generic list. With an active Tab membership, every covered strength is $0 — not a percentage off, not a coupon that changes month to month — at participating pharmacies nationwide or through mail order. You do not need insurance, and Tab works whether or not you have a health plan.
Tab is a membership, not insurance. Covered medications require a prescription from a licensed clinician.
Cephalexin dosage and administration
Adults and patients at least 15 years of age The usual dose is 250 mg every 6 hours, but a dose of 500 mg every 12 hours may be administered ( 2.1 ) Pediatric patients (over 1 year of age) Otitis media: 75 to 100 mg/kg in equally divided doses every 6 hours ( 2.2 ) All other indications: 25 to 50 mg/kg given in equally divided doses ( 2.2 ) In severe infections: 50 to 100 mg/kg may be administered in equally divided doses ( 2.2 ) Duration of therapy ranges from 7 to 14 days depending on the infection type and severity. ( 2 ) Dosage adjustment is required in patients with severe and end stage renal disease (ESRD) defined as creatinine clearance below 30 mL/min.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Your prescribing clinician decides the exact dose, form and schedule for you — this is not medical advice.
Cephalexin side effects
The following serious events are described in greater detail in the Warning and Precautions section: Hypersensitivity reactions [see Warning and Precautions (5.1) ] Clostridium difficile -associated diarrhea [see Warnings and Precautions (5.2) ] Direct Coombs’ Test Seroconversion [see Warnings and Precautions (5.3) ] Seizure Potential [see Warnings and Precautions (5.4) ] Effect on Prothrombin Activity [see Warnings and Precautions (5.5) ] Development of Drug-Resistant Bacteria [see Warnings and Precautions (5.6) ] The most common adverse reactions associated with cephalexin include diarrhea, nausea, vomiting, dyspepsia and abdominal pain . ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. This is not a complete list. Report side effects to your clinician, and seek care for anything severe or unexpected.
Cephalexin drug interactions
Metformin: increased metformin concentrations. Monitor for hypoglycemia. ( 7.1 ) Probenecid-The renal excretion of cephalexin is inhibited by probenecid. Co-administration of probenecid with cephalexin is not recommended. ( 7.2 ) Administration of cephalexin may result in a false-positive reaction glucose in the urine. ( 7.3 ) 7.1 Metformin Administration of cephalexin with metformin results in increased plasma metformin concentrations and decreased renal clearance of metformin. Careful patient monitoring and dose adjustment of metformin is recommended in patients concomitantly taking cephalexin and metformin [see Clinical Pharmacology (12.3) ]. 7.2 Probenecid The renal excretion of cephalexin is inhibited by probenecid. Co-administration of probenecid with cephalexin is not recommended.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Tell your clinician and pharmacist about every medication, supplement and over-the-counter product you take.
Who should not take cephalexin
Cephalexin capsules are contraindicated in patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. Patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. ( 4 )
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Whether this medication is appropriate for you is a clinical decision made by your prescribing clinician.
Common questions
Is cephalexin covered at $0 with Tab?
Yes. Cephalexin is on Tab's covered $0 generic list — every covered strength is $0 with an active membership, at participating pharmacies nationwide or by mail order.
Do I need insurance to get cephalexin through Tab?
No. Tab is a membership, not insurance. Covered medications are $0 with an active membership whether or not you have a health plan.
How do I get a cephalexin prescription with Tab?
Book a video visit with a licensed Tab clinician (unlimited visits are included with membership). If it's clinically appropriate, they send the prescription to your chosen participating pharmacy or by mail order.
How much does cephalexin cost without insurance?
Without insurance, retail cash prices for cephalexin vary by pharmacy, strength and quantity. Cephalexin is on Tab's covered $0 generic list, so every covered strength is $0 with an active Tab membership at participating pharmacies nationwide or by mail order.
What is the cheapest way to get cephalexin?
For medications on Tab's covered list, a Tab membership is the cheapest route: covered strengths of cephalexin are $0 with an active membership, and unlimited video visits with a licensed clinician are included, so the visit that produces the prescription is covered too.
What is the usual dose of cephalexin?
Adults and patients at least 15 years of age The usual dose is 250 mg every 6 hours, but a dose of 500 mg every 12 hours may be administered ( 2.1 ) Pediatric patients (over 1 year of age) Otitis media: 75 to 100 mg/kg in equally divided doses every 6 hours ( 2.2 ) All other indications: 25 to 50 mg/kg given in equally divided doses ( 2.2 ) In severe infections: 50 to 100 mg/kg may be administered in equally divided doses ( 2.2 ) Duration of therapy ranges from 7 to 14 days depending on the infection type and severity. (FDA-approved label, retrieved 2026-09-15. Your clinician sets your dose.)
What are the side effects of cephalexin?
The following serious events are described in greater detail in the Warning and Precautions section: Hypersensitivity reactions [see Warning and Precautions (5.1) ] Clostridium difficile -associated diarrhea [see Warnings and Precautions (5.2) ] Direct Coombs’ Test Seroconversion [see Warnings and Precautions (5.3) ] Seizure Potential [see Warnings and Precautions (5.4) ] Effect on Prothrombin Activity [see Warnings and Precautions (5.5) ] Development of Drug-Resistant Bacteria [see Warnings and Precautions (5.6) ] The most common adverse reactions associated with cephalexin include diarrhea, nausea, vomiting, dyspepsia and abdominal pain . (FDA-approved label, retrieved 2026-09-15.)
What interacts with cephalexin?
Metformin: increased metformin concentrations. Monitor for hypoglycemia. ( 7.1 ) Probenecid-The renal excretion of cephalexin is inhibited by probenecid. Co-administration of probenecid with cephalexin is not recommended. ( 7.2 ) Administration of cephalexin may result in a false-positive reaction glucose in the urine. (FDA-approved label, retrieved 2026-09-15. Tell your clinician about every medication and supplement you take.)
Cephalexin is $0 on the covered list
Members pay $0 for covered generics at participating pharmacies nationwide or by mail order — plus unlimited virtual primary care, urgent care and dermatology visits. No insurance needed.
Solo $49/mo · Family $119/mo for up to 4 people · Family+ $149/mo for up to 8
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