Drug & supplement interaction

Ketogenic Diet + Cephalexin

Cephalexin brand names: Keflex, Keftab, Cephalex, Lexin.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Ketogenic Diet and Cephalexin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Ketogenic Diet and Cephalexin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Cephalexin and Ketogenic Diet in our sources. This does not guarantee that the combination is completely free of risk — research on Ketogenic Diet alongside specific medications may be limited.

Ketogenic Diet is an eating pattern rather than something you take. Ask your pharmacist or doctor before changing how you eat while on a prescribed medicine: some medicines are dosed around meals, and a change in diet can change how they work. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Ketogenic Diet safety at a glance

Ketogenic Diet overall Use caution Generally manageable for healthy adults short-term, but it can cause side effects and is not safe for everyone.

Pregnancy Use caution Strict keto is generally not recommended in pregnancy without medical supervision because of nutrient and growth concerns.

Breastfeeding Possibly Unsafe When used orally without medical supervision. While rare, there are several case reports of lactation ketoacidosis thought to be associated with adherence to ca... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Cephalexin and Ketogenic Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Cephalexin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cephalexin is filed under 7 classifications — including organic anion transporter 3 (oat3) substrates, organic anion transporter 1 (oat1) substrates, antibiotic drugs. Ketogenic Diet has documented interactions with 6 drug classes — the most serious being anticonvulsants (moderate), antidiabetes drugs (moderate) and carbonic anhydrase inhibitors (moderate) — and none of Cephalexin’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Ketogenic Diet Does Interact With Other Medications

Ketogenic Diet has 137 moderate, 122 minor known drug interactions in our database — Cephalexin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 137 Minor 122 No known interaction 2,571 (incl. Cephalexin)

Taking anything else?

Check Another of Your Medications Against Ketogenic Diet

Covers the 2,830 medications we’ve checked against Ketogenic Diet. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Ketogenic Diet and Cephalexin May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so following Ketogenic Diet while taking the medicine can make those effects more likely to turn up, and harder to pin on one or the other if they do. 7 of them are worth acting on rather than waiting out — marked below.

Hallucinations Worth acting on Additional detail
Ketogenic Diet
“Psychosis or hallucinations have been reported in”

Ketogenic Diet · Natural Medicines adverse-effect record, reported in psychosis.
1 source cited

96903. Liu H, Yang Y, Wang Y, et al. Ketogenic diet for treatment of intractable epilepsy in adults: A meta-analysis of observational studies. Epilepsia Open. 2018;3(1):9-17. PubMed
Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›
Seizures Worth acting on Additional detail
Ketogenic Diet
“Increased risk of infection has been reported rarely, possibly related to low protein intake. Anaphylaxis associated with the ketogenic diet has also been reported rarely. In one case, a 6-year-old male developed a new-onset egg allergy with an anaphylactic reaction following a previous consumption of 10-15 eggs daily for 6 months as part of the ketogenic diet for epilepsy.”

Ketogenic Diet · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).
3 sources cited

98416. van der Louw E, van den Hurk D, Neal E, et al. Ketogenic diet guidelines for infants with refractory epilepsy. Eur J Paediatr Neurol. 2016;20(6):798-809. PubMed

96968. Ulamek-Koziol M, Pluta R, Bogucka-Kocka A, Czuczwar SJ. To treat or not to treat drug-refractory epilepsy by the ketogenic diet? That is the question. Ann Agric Environ Med. 2016;23(4):533-536. PubMed

97642. Levy Y, Peleg-Weiss L, Goldberg-Stern H. The modified Atkins diet for intractable epilepsy may be associated with late-onset egg-induced anaphylactic reaction: a case report. Nutrition. 2011;27(3):380-2.
“Hyperuricemia is a common mild and transient adverse effect related to a very low-calorie ketogenic diet in obese adults. It has also been reported with high-fat ketogenic diets in children with epilepsy and a few patients with cancer.

In a case report, hyponatremia thought to be related to the ketogenic diet occurred in an adult given the diet for super-refractory status epilepticus.”

Ketogenic Diet · Natural Medicines adverse-effect record, reported in anemia.
6 sources cited

96957. Martin-McGill KJ, Srikandarajah N, Marson AG, Tudur Smith C, Jenkinson MD. The role of ketogenic diets in the therapeutic management of adult and paediatric gliomas: a systematic review. CNS Oncol. 2018;7(2):CNS17.

96970. Zahra A, Fath MA, Opat E, et al. Consuming a ketogenic diet while receiving radiation and chemotherapy for locally advanced lung cancer and pancreatic cancer: The University of Iowa experience of two phase 1 clinical trials. Radiat Res. 2017;187(6):743-75 PubMed

96978. Winter SF, Loebel F, Dietrich J. Role of ketogenic metabolic therapy in malignant glioma: A systematic review. Crit Rev Oncol Hematol. 2017;112:41-58. PubMed

97650. Cai QY, Zhou ZJ, Luo R, et al. Safety and tolerability of the ketogenic diet used for the treatment of refractory childhood epilepsy: a systematic review of published prospective studies. World J Pediatr. 2017;13(6):528-536. PubMed

98415. Cervenka MC, Hocker S, Koenig M, et al. Phase I/II multicenter ketogenic diet study for adult superrefractory status epilepticus. Neurology. 2017;88(10):938-943. PubMed

100843. Chin A. Copper Deficiency Anemia and Neutropenia Due to Ketogenic Diet. Pediatrics. 2018;141(5). pii: e20173286. PubMed
Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›
A low platelet count / Bleeding or bruising Worth acting on Additional detail

Ketogenic Diet

“The ketogenic diet is generally well tolerated when followed for up to one year. Ketogenic diets have poor long-term tolerability and are usually not sustainable long-term.

Most Common Adverse Effects:

Dizziness, fatigue, headache, gastrointestinal discomfort, nausea, and weakness; these symptoms are sometimes referred to as the "keto flu".”

Ketogenic Diet · Natural Medicines adverse-effect record, reported in arrhythmia.

Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›
Kidney problems Worth acting on Additional detail
Ketogenic Diet
“Renal calculi have been reported to occur in as many as 7% of children and 7.9% of adults on the ketogenic diet, due to increased calcium in the blood and urine. The stones contain uric acid, calcium oxalate, and/or calcium phosphate. Discontinuation of the diet or lithotripsy are rarely needed. Oral citrates and adequate hydration are used to prevent stone formation.”

Ketogenic Diet · Natural Medicines adverse-effect record, reported in kidney stones (nephrolithiasis).
6 sources cited

98416. van der Louw E, van den Hurk D, Neal E, et al. Ketogenic diet guidelines for infants with refractory epilepsy. Eur J Paediatr Neurol. 2016;20(6):798-809. PubMed

98417. Kossoff EH, Zupec-Kania BA, Auvin S, et al. Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group. Epilepsia Open. 2018;3(2):175-192. PubMed

96903. Liu H, Yang Y, Wang Y, et al. Ketogenic diet for treatment of intractable epilepsy in adults: A meta-analysis of observational studies. Epilepsia Open. 2018;3(1):9-17. PubMed

96965. Hawkes CP, Levine MA. Ketotic hypercalcemia: a case series and description of a novel entity. J Clin Endocrinol Metab. 2014;99(5):1531-6. PubMed

97650. Cai QY, Zhou ZJ, Luo R, et al. Safety and tolerability of the ketogenic diet used for the treatment of refractory childhood epilepsy: a systematic review of published prospective studies. World J Pediatr. 2017;13(6):528-536. PubMed

108220. Acharya P, Acharya C, Thongprayoon C, et al. Incidence and characteristics of kidney stones in patients on ketogenic diet: A systematic review and meta-analysis. Diseases 2021;9(2):39. PubMed
Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›
Anemia / A low white blood cell count Worth acting on Additional detail

Ketogenic Diet

Recorded for Ketogenic Diet in the same Natural Medicines adverse-effect record shown under Seizures above.

Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›
Stomach upset Additional detail
Ketogenic Diet
“The most common adverse effect of the ketogenic diet is constipation, possibly requiring medication. Severe fecal impaction with a large stool bezoar that required a right hemicolectomy has been reported in a 6-week-old infant on ketogenic formula for refractory epilepsy. Other common mild adverse effects include vomiting, nausea, diarrhea, hunger, reflux, gas, and abdominal discomfort.”

Ketogenic Diet · Natural Medicines adverse-effect record, reported in constipation.
6 sources cited

98415. Cervenka MC, Hocker S, Koenig M, et al. Phase I/II multicenter ketogenic diet study for adult superrefractory status epilepticus. Neurology. 2017;88(10):938-943. PubMed

98417. Kossoff EH, Zupec-Kania BA, Auvin S, et al. Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group. Epilepsia Open. 2018;3(2):175-192. PubMed

96903. Liu H, Yang Y, Wang Y, et al. Ketogenic diet for treatment of intractable epilepsy in adults: A meta-analysis of observational studies. Epilepsia Open. 2018;3(1):9-17. PubMed

96957. Martin-McGill KJ, Srikandarajah N, Marson AG, Tudur Smith C, Jenkinson MD. The role of ketogenic diets in the therapeutic management of adult and paediatric gliomas: a systematic review. CNS Oncol. 2018;7(2):CNS17.

96978. Winter SF, Loebel F, Dietrich J. Role of ketogenic metabolic therapy in malignant glioma: A systematic review. Crit Rev Oncol Hematol. 2017;112:41-58. PubMed

97639. Ashrafi MR, Hosseini SA, Zamani GR, et al. The efficacy of the ketogenic diet in infants and young children with refractory epilepsies using a formula-based powder. Acta Neurol Belg. 2017;117(1):175-182. PubMed
Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›
Tiredness Additional detail
Ketogenic Diet
“Mild headaches, lethargy, and fatigue have been reported rarely, probably related to the reduction in carbohydrate intake. These symptoms are a part of a syndrome called the "keto flu" which sometimes occurs when initiating the ketogenic diet. In a few cases, seizures have worsened.”

Ketogenic Diet · Natural Medicines adverse-effect record, reported in epilepsy.
6 sources cited

96903. Liu H, Yang Y, Wang Y, et al. Ketogenic diet for treatment of intractable epilepsy in adults: A meta-analysis of observational studies. Epilepsia Open. 2018;3(1):9-17. PubMed

96954. Goday A, Bellido D, Sajoux I, et al. Short-term safety, tolerability and efficacy of a very low-calorie-ketogenic diet interventional weight loss program versus hypocaloric diet in patients with type 2 diabetes mellitus. Nutr Diabetes. 2016;6(9):e230. PubMed

96970. Zahra A, Fath MA, Opat E, et al. Consuming a ketogenic diet while receiving radiation and chemotherapy for locally advanced lung cancer and pancreatic cancer: The University of Iowa experience of two phase 1 clinical trials. Radiat Res. 2017;187(6):743-75 PubMed

96978. Winter SF, Loebel F, Dietrich J. Role of ketogenic metabolic therapy in malignant glioma: A systematic review. Crit Rev Oncol Hematol. 2017;112:41-58. PubMed

97650. Cai QY, Zhou ZJ, Luo R, et al. Safety and tolerability of the ketogenic diet used for the treatment of refractory childhood epilepsy: a systematic review of published prospective studies. World J Pediatr. 2017;13(6):528-536. PubMed

97651. Lin A, Turner Z, Doerrer SC, Stanfield A, Kossoff EH. Complications during ketogenic diet initiation: Prevalence, treatment, and influence on seizure outcomes. Pediatr Neurol. 2017;68:35-39.
Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›
Dizziness Additional detail

Ketogenic Diet

Recorded for Ketogenic Diet in the same Natural Medicines adverse-effect record shown under A low platelet count / Bleeding or bruising above.

Cephalexin

Listed in the ADVERSE REACTIONS section of the FDA label for Cephalexin. Read the label on DailyMed ›

Showing the 10 most notable of 14 shared effects — ranked by how unusual each one is, not just whether both lists mention it.

Reported for Ketogenic Diet but not commonly for Cephalexin: a higher chance of infection, a severe allergic reaction, blood clots and bone thinning.

Effects for Cephalexin come from the ADVERSE REACTIONS section of its FDA label; effects for Ketogenic Diet come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Ketogenic Diet in Pregnancy & Breastfeeding

Lactation Possibly Unsafe

When used orally without medical supervision. While rare, there are several case reports of lactation ketoacidosis thought to be associated with adherence to calorie-restricted and non-calorie-restricted ketogenic diets. The increased metabolic demand of breastfeeding, especially if exclusively breastfeeding, may increase the risk of lactation ketoacidosis in these individuals. In addition to metabolic changes, symptoms included nausea, vomiting, dizziness, dyspnea, lethargy, epigastric pain, and chest pain. In one case, the lactation ketoacidosis was life-threatening and required treatment in the intensive care unit with non-invasive ventilatory support and dextrose and insulin infusions. In this case, the patient was following a calorie-restricted, ketogenic diet and had lost 19 pounds over 3 weeks.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Ketogenic Diet or Cephalexin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Ketogenic Diet or Cephalexin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Cephalexin

This page covers Ketogenic Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cephalexin page lists 61 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate) and Aristolochia (moderate).

By severity: 3 major · 47 moderate · 11 minor.

From our pharmacist’s overview on the Cephalexin page

“Cephalexin (Keflex) is one of the most commonly prescribed oral antibiotics, usually for skin and urinary infections, and its supplement list warrants genuine care rather than a quick skim. Three of the 61 ingredients on file rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Cephalexin interaction page

How much people look this up

Where Ketogenic Diet and Cephalexin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Ketogenic Diet

Steady interest

#1,206 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Cephalexin

Top 5%

#67 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Ketogenic Diet reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Ketogenic Diet and Cephalexin records this page draws on were last updated July 11, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Eating pattern

About Ketogenic Diet

What is Ketogenic Diet?

Weight loss
Type 2 diabetes and blood sugar control
Drug-resistant epilepsy (especially in children)
Reducing appetite
Athletic and metabolic interest

The ketogenic diet is a very low-carbohydrate, high-fat eating plan that shifts the body to burn fat for fuel. It has the strongest evidence as a medical therapy for hard-to-treat epilepsy and may help short-term weight loss and blood sugar, but it can be hard to sustain and is not right for everyone. Talk with a doctor or pharmacist before starting, especially if you have a medical condition or take medication.

Whole-food eating plan; sometimes paired with MCT oil or exogenous ketone supplements

An interaction check asks whether these two react with each other — it does not ask whether Ketogenic Diet is a good idea for someone in your situation. Here is what our Ketogenic Diet record says about it on its own.

Ketogenic Diet: dosing

There is no single "dose" for a ketogenic diet. Instead, it is defined by how much of your calories come from fat, protein, and carbohydrates. Strict therapeutic versions used for epilepsy keep carbohydrates very low and are calculated carefully by a medical team. More relaxed low-carb versions allow somewhat more carbohydrate.If you try keto on your own, follow guidance from a reputable source and pay attention to food quality, hydration, and electrolytes. Children should only follow a medical ketogenic diet under specialist supervision.

From our Ketogenic Diet monograph — the full record covers uses, side effects and every documented interaction.

Read the full Ketogenic Diet monograph & all interactions

Medication

About Cephalexin

What Is Cephalexin Used For?

Brand names: Keflex, Keftab, Cephalex, Lexin

Cephalexin treats bacterial infections caused by susceptible strains of bacteria. It is used for respiratory tract infections, ear infections (otitis media), skin and skin structure infections, bone infections, and genitourinary tract infections — including acute prostatitis.

It works only against bacterial infections — not viruses like colds or flu. Your prescriber should use it only when a bacterial infection is confirmed or strongly suspected, to help prevent antibiotic resistance.

Most-Reported Side Effects for Cephalexin

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Chronic kidney disease 2,157 reports

Renal failure 1,558 reports

Acute kidney injury 1,550 reports

Diarrhea 1,405 reports

Fatigue 1,303 reports

See full Cephalexin drug information

Keep checking

Other Drugs & Ketogenic Diet

Browse every other medication we’ve checked against Ketogenic Diet — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major

137Moderate

122Minor

2,570No known interaction

137 Moderate 122 Minor 2,570 No interaction

Moderate

137 interactions

Showing 60 of 137 moderate interactions — see all 137 on the Ketogenic Diet page.

Minor

122 interactions

Showing 60 of 122 minor interactions — see all 122 on the Ketogenic Diet page.

No interaction 2,570 drugs checked — show the list

We also checked Ketogenic Diet against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,570 medications checked with no known interaction — see the full Ketogenic Diet list.

See the full Ketogenic Diet interactions page

See every supplement checked against Cephalexin, ranked by severity

Evidence & sources

Ketogenic Diet References

The 72 references that drive our Ketogenic Diet monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Liu H, Yang Y, Wang Y, et al. Ketogenic diet for treatment of intractable epilepsy in adults: A meta-analysis of observational studies. Epilepsia Open. 2018;3(1):9-17. PubMed
Yancy WS Jr, Westman EC, McDuffie JR, et al. A randomized trial of a low-carbohydrate diet vs orlistat plus a low-fat diet for weight loss. Arch Intern Med. 2010;170(2):136-45. PubMed
Goday A, Bellido D, Sajoux I, et al. Short-term safety, tolerability and efficacy of a very low-calorie-ketogenic diet interventional weight loss program versus hypocaloric diet in patients with type 2 diabetes mellitus. Nutr Diabetes. 2016;6(9):e230. PubMed
Saslow LR, Mason AE, Kim S, et al. An online intervention comparing a very low-carbohydrate ketogenic diet and lifestyle recommendations versus a plate method diet in overweight individuals with type 2 diabetes: A randomized controlled trial. J Med Intern
Hussain TA, Mathew TC, Dashti AA, Asfar S, Al-Zaid N, Dashti HM. Effect of low-calorie versus low-carbohydrate ketogenic diet in type 2 diabetes. Nutrition. 2012;28(10):1016-21. PubMed
Martin-McGill KJ, Srikandarajah N, Marson AG, Tudur Smith C, Jenkinson MD. The role of ketogenic diets in the therapeutic management of adult and paediatric gliomas: a systematic review. CNS Oncol. 2018;7(2):CNS17.
Michaels JD, Hoss E, DiCaudo DJ, Price H. Prurigo pigmentosa after a strict ketogenic diet. Pediatr Dermatol. 2015;32(2):248-51. PubMed
Hawkes CP, Levine MA. Ketotic hypercalcemia: a case series and description of a novel entity. J Clin Endocrinol Metab. 2014;99(5):1531-6. PubMed
Lima PA, de Brito Sampaio LP, Damasceno NR. Ketogenic diet in epileptic children: impact on lipoproteins and oxidative stress. Nutr Neurosci. 2015;18(8):337-44. PubMed
Ulamek-Koziol M, Pluta R, Bogucka-Kocka A, Czuczwar SJ. To treat or not to treat drug-refractory epilepsy by the ketogenic diet? That is the question. Ann Agric Environ Med. 2016;23(4):533-536. PubMed
Zahra A, Fath MA, Opat E, et al. Consuming a ketogenic diet while receiving radiation and chemotherapy for locally advanced lung cancer and pancreatic cancer: The University of Iowa experience of two phase 1 clinical trials. Radiat Res. 2017;187(6):743-75 PubMed
Ahn WK, Park S, Kim HD. Protein-losing enteropathy as a complication of the ketogenic diet. Yonsei Med J. 2017;58(4):891-893. PubMed
Winter SF, Loebel F, Dietrich J. Role of ketogenic metabolic therapy in malignant glioma: A systematic review. Crit Rev Oncol Hematol. 2017;112:41-58. PubMed
Kverneland M, Selmer KK, Nakken KO, Iversen PO, Taubøll E. A prospective study of the modified Atkins diet for adults with idiopathic generalized epilepsy. Epilepsy Behav. 2015;53:197-201. PubMed
Ashrafi MR, Hosseini SA, Zamani GR, et al. The efficacy of the ketogenic diet in infants and young children with refractory epilepsies using a formula-based powder. Acta Neurol Belg. 2017;117(1):175-182. PubMed
Levy Y, Peleg-Weiss L, Goldberg-Stern H. The modified Atkins diet for intractable epilepsy may be associated with late-onset egg-induced anaphylactic reaction: a case report. Nutrition. 2011;27(3):380-2.
Bertoli S, Trentani C, Ferraris C, De Giorgis V, Veggiotti P, Tagliabue A. Long-term effects of a ketogenic diet on body composition and bone mineralization in GLUT-1 deficiency syndrome: a case series. Nutrition. 2014;30(6):726-8. PubMed
Desai AA, Thompson LM, Abdelmoity AT, Kayyali H, St Peter SD. Management of symptomatic cholelithiasis while on ketogenic diet: a case report. Pediatr Neurol. 2014;51(3):439-40. PubMed
Moriyama K, Watanabe M, Yamada Y, Shiihara T. Protein-losing enteropathy as a rare complication of the ketogenic diet. Pediatr Neurol. 2015;52(5):526-8. PubMed
Klepper J, Leiendecker B, Heussinger N, Lausch E, Bosch F. Severe hypertriglyceridemia in Glut1D on ketogenic Diet. Neuropediatrics. 2016;47(2):132-6. PubMed
Wing RR, Vazquez JA, Ryan CM. Cognitive effects of ketogenic weight-reducing diets. Int J Obes Relat Metab Disord. 1995;19(11):811-6.
Cai QY, Zhou ZJ, Luo R, et al. Safety and tolerability of the ketogenic diet used for the treatment of refractory childhood epilepsy: a systematic review of published prospective studies. World J Pediatr. 2017;13(6):528-536. PubMed
Lin A, Turner Z, Doerrer SC, Stanfield A, Kossoff EH. Complications during ketogenic diet initiation: Prevalence, treatment, and influence on seizure outcomes. Pediatr Neurol. 2017;68:35-39.
Melchior RW, Dreher M, Ramsey E, Savoca M, Rosenthal T. Cardiopulmonary bypass considerations for pediatric patients on the ketogenic diet. Perfusion. 2015;30(5):423-6. PubMed
Kverneland M, Taubøll E, Selmer KK, Iversen PO, Nakken KO. Modified Atkins diet may reduce serum concentrations of antiepileptic drugs. Acta Neurol Scand. 2015;131(3):187-90. PubMed
Cervenka MC, Hocker S, Koenig M, et al. Phase I/II multicenter ketogenic diet study for adult superrefractory status epilepticus. Neurology. 2017;88(10):938-943. PubMed
van der Louw E, van den Hurk D, Neal E, et al. Ketogenic diet guidelines for infants with refractory epilepsy. Eur J Paediatr Neurol. 2016;20(6):798-809. PubMed
Kossoff EH, Zupec-Kania BA, Auvin S, et al. Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group. Epilepsia Open. 2018;3(2):175-192. PubMed
Chin A. Copper Deficiency Anemia and Neutropenia Due to Ketogenic Diet. Pediatrics. 2018;141(5). pii: e20173286. PubMed
Alkeraye S, AlMuqrin A, AlQahtani SM, AlSwayyed M, Alhuzimi A. Twenty-five year-old female with sudden onset itchy skin eruption over her upper back and chest three weeks after starting a ketogenic diet. Ann Saudi Med. 2019;39(6):444-445. PubMed
Draaisma JMT, Hampsink BM, Janssen M, van Houdt NBM, Linders ETAM, Willemsen MA. The Ketogenic Diet and Its Effect on Bone Mineral Density: A Retrospective Observational Cohort Study. Neuropediatrics. 2019;50(6):353-358. PubMed
Heikura IA, Burke LM, Hawley JA, et al. A Short-Term Ketogenic Diet Impairs Markers of Bone Health in Response to Exercise. Front Endocrinol (Lausanne) 2020;10:880. PubMed
Dressler A, Chiara H, Benninger F, et al. Effects of the ketogenic diet on platelet counts and global coagulation tests in childhood epilepsy. Seizure. 2020;80:31-37. PubMed
Lonowski S, Levins P. A unique case of prurigo pigmentosa related to ketogenic diet. Dermatol Online J 2020;26(2):13030/qt56p0z9rp. DOI
Rana AM, Mansoor K, Assad S, Abouzid M, Ogu I, Bandak GSI. Severe Metabolic Acidosis: A Case of Triple Hit with Ketogenic Diet, Vinegar, and Metformin in an Obese Patient. Case Rep Nephrol 2020;2020:8861978. PubMed
Sudhakaran S, Yazdani L, Wheelan KR, Rao PK. The ketogenic diet and the QT interval. Proc (Bayl Univ Med Cent) 2019;33(1):77-79. PubMed
Kverneland M, Taubøll E, Molteberg E, Veierød MB, Selmer KK, Nakken KO, Iversen PO. Pharmacokinetic interaction between modified Atkins diet and antiepileptic drugs in adults with drug-resistant epilepsy. Epilepsia. 2019;60(11):2235-2244. PubMed
Kirkpatrick CF, Bolick JP, Kris-Etherton PM, et al. Review of current evidence and clinical recommendations on the effects of low-carbohydrate and very-low-carbohydrate (including ketogenic) diets for the management of body weight and other cardiometaboli
Shahrigharahkoshan S, AlHalees Z, Pehr K. Ketogenic diet-induced prurigo pigmentosa: a rising association. Int J Dermatol 2022;61(7):779-782. PubMed
Choi J, Young TL, Chartier LB. Recurrent acute pancreatitis during a ketogenic diet-a case report and literature review. Int J Emerg Med 2021;14(1):52. PubMed
Kishk NA, Yousof HZ, Ebraheim AM, et al. The effect of ketogenic diet escalation in adolescents and adults with drug-resistant epilepsy: a prospective study. Nutr Neurosci 2021. PubMed
Acharya P, Acharya C, Thongprayoon C, et al. Incidence and characteristics of kidney stones in patients on ketogenic diet: A systematic review and meta-analysis. Diseases 2021;9(2):39. PubMed
Yilmaz Ü, Edizer S, Köse M, et al. The effect of ketogenic diet on serum lipid concentrations in children with medication resistant epilepsy. Seizure 2021;91:99-107. PubMed
Xiao A, Kopelman H, Shitabata P, Nami N. Ketogenic diet-induced prurigo pigmentosa (the "Keto Rash"): A case report and literature review. J Clin Aesthet Dermatol 2021;14(12 Suppl 1):S29-S32.
Javaid S, Lindenberg A, Srinivasan R. Can the ketogenic diet lead to Wernicke's encephalopathy?. J Pediatr Rehabil Med 2022;15(2):335-340. PubMed
Lu LY, Chen CB. Keto Rash: Ketoacidosis-induced prurigo pigmentosa. Mayo Clin Proc 2022;97(1):20-21. PubMed
Osborne KC, Oliver JJ. Lactation ketoacidosis induced by breastfeeding while on a ketogenic diet. Am J Emerg Med 2022;56:392.e5-392.e6. PubMed
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Rafiullah M, Musambil M, David SK. Effect of a very low-carbohydrate ketogenic diet vs recommended diets in patients with type 2 diabetes: a meta-analysis. Nutr Rev 2022;80(3):488-502. PubMed
Chan JT, Mude PJ, Canfield W, Makhija J, Yap JEL. Severe hypertriglyceridemia-induced necrotizing pancreatitis associated with ketogenic diet in a well-controlled patient with type 2 diabetes mellitus. Cureus 2022;14(1):e20879. PubMed
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Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Related: nutrient depletion

Cephalexin Is Linked to Lower Levels of 7 Nutrients

Natural Medicines records Cephalexin as a medicine that can lower these. This is not an interaction with Ketogenic Diet — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:

Read the full Cephalexin nutrient depletion report ›

Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.

Pharmacist Counseling Corner

Following Ketogenic Diet While Taking Cephalexin: Common Questions

Is it safe to follow Ketogenic Diet while taking Cephalexin?

We do not list a known interaction between Ketogenic Diet and Cephalexin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

Do Ketogenic Diet and Cephalexin have any of the same side effects?

Yes — our sources link each of them separately to 10 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

How was the Ketogenic Diet and Cephalexin combination checked?

Interactions in our licensed database are recorded against drug classes. Cephalexin is filed under 7 classifications, and Ketogenic Diet has documented interactions with 6 drug classes — none of Cephalexin's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does Ketogenic Diet interact with any other medications?

Yes. Ketogenic Diet has 259 documented drug interactions in our database — Cephalexin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Cephalexin interact with any supplements?

Yes. Cephalexin has documented interactions with 61 supplements in our database — Ketogenic Diet is not one of them. The Cephalexin interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Ketogenic Diet monograph Uses, safety profile, and every drug interaction in one place Cephalexin drug information The full plain-English guide to this medication Cephalexin supplement interactions Every supplement checked against Cephalexin, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 72 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.