Drug & supplement interaction

Ketogenic Diet + Letrozole

Letrozole brand name: Femara.

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 Letrozole 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.

Know someone interested in this? Share

Facebook Post Reddit Email

On this page

Interaction report

Ketogenic Diet and Letrozole

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 Letrozole 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 Letrozole and Ketogenic Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Letrozole

Interactions in our licensed database are recorded against drug classes, not just single drug names. Letrozole is filed under 4 classifications — including aromatase inhibitors, cytochrome p450 2c19 (cyp2c19) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates. 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 Letrozole’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 — Letrozole 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. Letrozole)

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 Letrozole 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. One of them is worth acting on rather than waiting out — marked below.

Bleeding or bruising Worth acting on Additional detail
Ketogenic Diet
“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
Letrozole

Listed in the ADVERSE REACTIONS section of the FDA label for Letrozole. Read the label on DailyMed ›
Muscle pain Additional detail
Ketogenic Diet
“The ketogenic diet decreases bone mineral density (BMD) and increases the risk of bone fractures when used in children, especially those on antiseizure medication. Supplementation with calcium and vitamin D helps to mitigate these risks but does not eliminate them. The ketogenic diet seems to increase bone calcium loss.”

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

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

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

102190. 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

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

96907. 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

105651. 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
Letrozole

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

Listed in the ADVERSE REACTIONS section of the FDA label for Letrozole. Read the label on DailyMed ›
Tiredness / Headache 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.
Letrozole

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

Ketogenic Diet

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

Letrozole

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

Ketogenic Diet

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

Letrozole

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

Reported for Ketogenic Diet but not commonly for Letrozole: stomach upset, a higher chance of infection, a severe allergic reaction and blood clots.

Effects for Letrozole 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

Overlapping uses

What Letrozole Is Prescribed For, and What Ketogenic Diet Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Letrozole is a prescription medicine with approved uses on its FDA label. Ketogenic Diet is an eating pattern: what follows is what researchers have looked at it for, and how strong that evidence is.

Letrozole is prescribed for: Letrozole (brand name Femara) is used to treat breast cancer in postmenopausal women whose tumors are driven by estrogen. It is used in three settings: as adjuvant (after-surgery) treatment for hormone receptor positive early breast cancer; as extended adjuvant treatment for women who have already completed about five years of tamoxifen therapy; and as first- or second-line treatment for locally advanced or metastatic (spread) breast cancer. Femara is specifically indicated for first-line treatment of hormone receptor positive or receptor-unknown locally advanced or metastatic breast cancer, and for advanced breast cancer in women whose disease has progressed after antiestrogen therapy.

Ketogenic Diet has been studied for:

Breast cancer studied, not established Ketogenic Diet has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

Ketogenic Diet for breast cancer

It is unclear if following the ketogenic diet is beneficial in patients with breast cancer.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Letrozole on your own; if you are taking Ketogenic Diet for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Ketogenic Diet or Letrozole

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 Letrozole, 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 Letrozole

This page covers Ketogenic Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Letrozole page lists 142 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), 7-methoxyflavone (moderate) and Acacia Rigidula (moderate).

By severity: 3 major · 99 moderate · 40 minor.

From our pharmacist’s overview on the Letrozole page

“Letrozole (Femara) is prescribed to keep hormone-driven breast cancer from returning, so a supplement that shifts its blood level can quietly undercut treatment. Give this list of 142 ingredients genuine respect, and learn the three major entries first.”

Reviewed by 2 · Jul 18, 2026

Open the Letrozole interaction page

How much people look this up

Where Ketogenic Diet and Letrozole 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

#1,221 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Letrozole

Top 5%

#48 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 Letrozole 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 Letrozole

What Is Letrozole Used For?

Brand name: Femara

Letrozole (brand name Femara) is used to treat breast cancer in postmenopausal women whose tumors are driven by estrogen. It is used in three settings: as adjuvant (after-surgery) treatment for hormone receptor positive early breast cancer; as extended adjuvant treatment for women who have already completed about five years of tamoxifen therapy; and as first- or second-line treatment for locally advanced or metastatic (spread) breast cancer.

Femara is specifically indicated for first-line treatment of hormone receptor positive or receptor-unknown locally advanced or metastatic breast cancer, and for advanced breast cancer in women whose disease has progressed after antiestrogen therapy.

See full Letrozole 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 Letrozole, 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
Sun HY, Sebaratnam DF. Prurigo pigmentosa following a ketogenic diet: a case report. Eur J Clin Nutr 2022;76(4):624-625. PubMed
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
Guirguis H, Beroukhim Afrahimi S, Pham C. The use of SGLT-2 inhibitors coupled with a strict low-carbohydrate diet: A set-up for inducing severe diabetic ketoacidosis. Clin Med Insights Case Rep 2022;15:11795476221090045. PubMed
Nnodum BN, Oduah E, Albert D, Pettus M. Ketogenic diet-induced severe ketoacidosis in a lactating woman: A case report and review of the literature. Case Rep Nephrol. 2019;2019:1214208. PubMed
Hong MJ, Schwartz LE, Ward HH, Morgan JC, Jacoby JL. Metabolic acidosis in a lactating woman induced by a deliberate ketogenic diet. JAAPA. 2021;34(12):31-33. PubMed
Stewart WA, Gordon K, Camfield P. Acute pancreatitis causing death in a child on the ketogenic diet. J Child Neurol. 2001;16(9):682. PubMed
Alkhouri F, Alkhouri S, Potts GA. Prurigo pigmentosa following a keto diet and bariatric surgery. Cureus 2022;14(4):e24307. PubMed
Huang L, Li H, Zhong J, et al. Efficacy and safety of the ketogenic diet for mitochondrial disease with epilepsy: A prospective, open-labeled, controlled study. Front Neurol 2022;13:880944. PubMed
Archna, Garg D, Goel S, et al. Modified Atkins diet versus levetiracetam for non-surgical drug-resistant epilepsy in children: A randomized open-label study. Seizure 2022;103:61-67. PubMed
Perez N, Langlest F, Mallet L, et al. Psilocybin-assisted therapy for depression: A systematic review and dose-response meta-analysis of human studies. Eur Neuropsychopharmacol 2023;76:61-76. PubMed
El-Shafie AM, Bahbah WA, Abd El Naby SA, et al. Impact of two ketogenic diet types in refractory childhood epilepsy. Pediatr Res 2023;94(6):1978-1989. PubMed
Caprio M, Moriconi E, Camajani E, et al. Very-low-calorie ketogenic diet vs hypocaloric balanced diet in the prevention of high-frequency episodic migraine: the EMIKETO randomized, controlled trial. J Transl Med 2023;21(1):692. PubMed
Løkken N, Nielsen MR, Stemmerik MG, et al. Can a modified ketogenic diet be a nutritional strategy for patients with McArdle disease? Results from a randomized, single-blind, placebo-controlled, cross-over study. Clin Nutr 2023;42(11):2124-2137. PubMed
Stegall C, Evans MC, Hollinger LE, Walz AA. Keto-Bezoar: Adverse Event Related to Initiation of Ketogenic Diet in an Infant. JPGN Rep 2022;3(2):e179.
Sharma S, Dabla S, Kaushik JS. Modified Atkins Diet vs. Ketogenic Diet in the Management of Children with Epileptic Spasms Refractory to First Line Treatment: An Open Labelled, Randomized Controlled Trial. Indian J Pediatr 2023;90(10):969-973. PubMed
Schoeler NE, Marston L, Lyons L, et al. Classic ketogenic diet versus further antiseizure medicine in infants with drug-resistant epilepsy (KIWE): a UK, multicentre, open-label, randomised clinical trial. Lancet Neurol 2023;22(12):1113-1124. PubMed
Ward KE, Ramsay J, Vu BJ. A Case of Severe Metabolic Acidosis in the Setting of a Strict Ketogenic Diet. Cureus 2023;15(5):e38741. PubMed
Nellore A, Maher E, Abate M. Prurigo Pigmentosa Induced by a Ketogenic Diet. Cureus 2023;15(5):e39498. PubMed
Naveh N, Avidan Y, Zafrir B. Extreme Hypercholesterolemia Following a Ketogenic Diet: Exaggerated Response to an Increasingly Popular Diet. Cureus 2023;15(8):e43683. PubMed
Thompson L, Sullivan DK, Varghese K, et al. Factors Associated With Growth in Patients Treated With the Classic Ketogenic Diet for Drug-Resistant Epilepsy. Pediatr Neurol 2023;146:110-115. PubMed
Borhan MK, Vethakkan SR, Sarvanandan T, Paramasivam SS. A Case of Severe Lactation Ketoacidosis in a Nondiabetic Mother on a Ketogenic Diet. JCEM Case Rep 2023;1(6):luad134. PubMed
Ayele GM, Atalay RT, Mamo RT, et al. Is Losing Weight Worth Losing Your Kidney: Keto Diet Resulting in Renal Failure. Cureus 2023;15(3):e36546. PubMed
Dickmann S, Carter D. 44-year-old man • elevated total cholesterol • chest pains • ketogenic diet • Dx?. J Fam Pract 2023;72(2):87-88.
Pedersen S, Kverneland M, Rudi K, et al. Decreased serum concentrations of antiseizure medications in children with drug resistant epilepsy following treatment with ketogenic diet. Epilepsia Open. 2023;8(3):858-866. PubMed

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.

Pharmacist Counseling Corner

Following Ketogenic Diet While Taking Letrozole: Common Questions

Is it safe to follow Ketogenic Diet while taking Letrozole?

We do not list a known interaction between Ketogenic Diet and Letrozole. 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 Letrozole have any of the same side effects?

Yes — our sources link each of them separately to 7 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.

Are Ketogenic Diet and Letrozole used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Ketogenic Diet in each. That is a conversation for your prescriber, especially if Letrozole is being adjusted to a target.

How was the Ketogenic Diet and Letrozole combination checked?

Interactions in our licensed database are recorded against drug classes. Letrozole is filed under 4 classifications, and Ketogenic Diet has documented interactions with 6 drug classes — none of Letrozole'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 — Letrozole 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 Letrozole interact with any supplements?

Yes. Letrozole has documented interactions with 142 supplements in our database — Ketogenic Diet is not one of them. The Letrozole 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 Letrozole drug information The full plain-English guide to this medication Letrozole supplement interactions Every supplement checked against Letrozole, 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

Still Have a Question About Letrozole and Ketogenic Diet?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.