A 2026 animal study found that a ketogenic diet altered how the liver processes ozanimod, a multiple sclerosis medication, resulting in approximately 17% higher drug levels in the blood. According to Gram Research analysis, the keto diet changed the activity of liver enzymes responsible for breaking down the medication, though this increase wasn’t statistically significant. People with MS taking ozanimod should consult their doctor before starting a ketogenic diet, as dietary changes may affect medication levels and effectiveness.
A new study looked at whether eating a ketogenic diet (very high fat, very low carb) could affect how the body breaks down ozanimod, a medication used to treat multiple sclerosis. Researchers fed mice either a normal diet or a keto diet for 4 weeks, then measured how their bodies processed the drug. They found that the keto diet changed which enzymes in the liver break down medications, and ozanimod levels in the blood were about 17% higher in keto-fed mice. While this difference wasn’t quite statistically significant, it suggests that diet choices might matter when taking certain medications.
Key Statistics
A 2026 animal study published in PLOS ONE found that mice on a ketogenic diet showed approximately 17% higher blood levels of ozanimod, a multiple sclerosis medication, compared to mice on a standard diet, though this difference did not reach statistical significance.
According to Gram Research analysis of this 2026 study, the ketogenic diet significantly increased the activity of the liver enzyme CYP1A while decreasing CYP2C activity, both of which are involved in breaking down ozanimod and other medications.
The 2026 research demonstrated that a ketogenic diet (90% of calories from fat) for 4 weeks altered gut bacteria composition and raised cholesterol levels in mice, alongside changes in drug-metabolizing enzymes.
The Quick Take
- What they studied: Whether eating a ketogenic diet (mostly fat, very few carbs) changes how the body processes ozanimod, a drug used to treat multiple sclerosis.
- Who participated: Female laboratory mice (C57BL/6 strain) were divided into two groups: one eating a normal diet with 10% fat calories and another eating a ketogenic diet with 90% fat calories for 4 weeks.
- Key finding: The ketogenic diet changed how liver enzymes work, leading to about 17% higher levels of ozanimod in the blood of keto-fed mice, though this increase wasn’t statistically proven.
- What it means for you: If you take ozanimod for MS and are considering a ketogenic diet, talk to your doctor first. Your medication levels might change, which could affect how well it works or cause side effects. This research is early-stage (animal study), so more human research is needed before making any diet changes.
The Research Details
Scientists divided female mice into two groups and fed them different diets for 4 weeks. One group ate a standard diet where 10% of their calories came from fat. The other group ate a ketogenic diet where 90% of their calories came from fat. After 4 weeks, researchers measured many things: blood sugar levels, cholesterol, inflammation markers, and the composition of bacteria in the mice’s guts. They also looked at the liver to see which enzymes were active and how much they were working. Finally, they gave the mice ozanimod and measured how much of the drug was in their blood over time.
This type of study is called a preclinical or animal study. It’s an important first step before testing ideas in humans, because it lets researchers control everything carefully and measure things that would be hard to measure in people. However, results in mice don’t always apply to humans, so this is really just the beginning of understanding this potential interaction.
Understanding how diet affects drug metabolism is crucial because it could explain why some people respond differently to the same medication. If the ketogenic diet really does change how ozanimod is processed in humans, doctors would need to know this to adjust doses or monitor patients more carefully. This is especially important for people with multiple sclerosis who might want to try keto as a complementary therapy alongside their medication.
This study was published in PLOS ONE, a reputable peer-reviewed journal. The researchers used standard laboratory methods and measured multiple related factors (liver enzymes, gut bacteria, blood markers). However, this is an animal study in mice, not humans, so the results may not directly apply to people. The sample size of mice wasn’t specified in the abstract. The increase in ozanimod levels (17%) didn’t reach statistical significance, meaning it could have happened by chance. More research, especially in humans, is needed to confirm these findings.
What the Results Show
The ketogenic diet successfully put the mice into ketosis (a metabolic state where the body burns fat for energy instead of carbs). As expected, this diet caused cholesterol levels to rise significantly in the blood. The researchers also found that the keto diet changed the composition of bacteria living in the mice’s guts, which makes sense because diet directly affects which bacteria thrive.
Most importantly, the keto diet altered how liver enzymes work. These enzymes, called cytochrome P450 enzymes, are responsible for breaking down many medications in the body. Specifically, the enzyme CYP1A became more active in keto-fed mice, while CYP2C activity decreased. CYP3A showed a trend toward lower activity but the difference wasn’t statistically significant.
Because ozanimod is broken down by these liver enzymes, the changes in enzyme activity led to higher levels of ozanimod in the blood of keto-fed mice. The drug’s exposure increased by about 17%, meaning more of the medication stayed in the body longer. However, this 17% increase didn’t reach statistical significance, which means researchers can’t be completely certain it wasn’t just random variation.
The study found that most other metabolic and inflammatory markers showed only modest changes with the ketogenic diet. This suggests that while keto does change how the body processes drugs, it doesn’t cause dramatic changes in overall inflammation or most other blood markers. The changes in gut bacteria composition were notable, as diet is known to shape the microbial community in the digestive system, and these bacteria may indirectly influence drug metabolism.
This research adds to growing evidence that diet can influence how medications are processed. Previous studies have shown that various foods and dietary patterns can affect drug metabolism, but there’s been little research on ketogenic diets specifically. This study is among the first to examine keto’s effects on a specific MS medication, filling an important gap as more people with MS explore keto as a complementary therapy.
This study has several important limitations. First, it was conducted in mice, not humans, so the results may not directly apply to people. Second, the sample size of mice wasn’t clearly reported, making it hard to judge how reliable the findings are. Third, the 17% increase in ozanimod levels didn’t reach statistical significance, meaning it could have occurred by chance. Fourth, this was a short-term study (4 weeks), so we don’t know what happens with longer-term keto use. Finally, the study only looked at female mice, so results might differ in males or in people of different sexes.
The Bottom Line
This is early-stage research in animals, so no clinical recommendations can be made yet. However, people with MS who are considering a ketogenic diet should discuss this with their neurologist before starting. If you’re taking ozanimod or similar medications, your doctor may want to monitor your medication levels more closely if you switch to a keto diet. Do not change your diet or medication without medical guidance. (Confidence level: Low—animal study only, non-significant findings)
This research is most relevant to people with multiple sclerosis who take ozanimod and are considering a ketogenic diet. It’s also important for doctors who treat MS patients and prescribe ozanimod. People taking other medications that are processed by the same liver enzymes (CYP1A, CYP2C, CYP3A) might also want to discuss dietary changes with their healthcare provider. This research is less immediately relevant to people without MS or those not taking these medications.
Since this is an animal study, we don’t yet know how quickly changes would occur in humans or how long they would last. The mice were studied for 4 weeks, which is a relatively short time. If similar effects occur in humans, changes in medication levels might happen within days to weeks of starting a keto diet, but more research is needed to determine this.
Frequently Asked Questions
Can the keto diet affect how my MS medication works?
Research suggests it may. A 2026 study found that ketogenic diet altered liver enzymes that break down ozanimod, resulting in 17% higher drug levels. If you take MS medications and want to try keto, discuss this with your neurologist first, as medication levels might change.
Should I avoid the ketogenic diet if I take ozanimod?
Not necessarily, but you should talk to your doctor first. This animal study suggests a potential interaction, but human research is needed. Your doctor can monitor you closely if you decide to try keto while taking ozanimod, watching for changes in symptom control or side effects.
How does diet change the way my body processes medication?
Diet affects the liver enzymes that break down drugs. The ketogenic diet changed which enzymes were active in this study, altering how quickly the body processes ozanimod. Gut bacteria, which diet influences, may also play a role in medication metabolism.
Is this study proof that keto affects MS medications in humans?
No. This was an animal study in mice, not humans. The 17% increase in drug levels also didn’t reach statistical significance. More research in people is needed before drawing firm conclusions about keto and MS medication interactions.
What should I do if I want to try the keto diet with my MS medication?
Schedule an appointment with your neurologist before starting. Tell them you’re interested in keto and ask them to monitor your medication levels and symptom control more closely. Keep detailed records of your diet, symptoms, and any side effects to share with your doctor.
Want to Apply This Research?
- If you take ozanimod and are considering keto, work with your doctor to track symptom control and any side effects weekly. Log: (1) adherence to your diet plan (% of days following keto), (2) MS symptom severity on a 1-10 scale, (3) any new side effects, and (4) medication timing and doses. This data helps your doctor spot any changes in how well your medication is working.
- Before making any dietary changes, schedule a conversation with your neurologist or prescribing doctor. Share your interest in trying a ketogenic diet and ask them to monitor you more closely if you proceed. Set a reminder to report any changes in how you feel, including new fatigue, worsening symptoms, or unexpected side effects. Keep a simple log of what you eat and how you feel each day.
- Create a monthly check-in with your healthcare provider if you’re combining keto with ozanimod. Track three key metrics: (1) disease activity (relapses or symptom changes), (2) medication side effects, and (3) diet adherence. Use the app to set weekly reminders to log these items and generate a monthly report to share with your doctor. This helps catch any problems early.
This research is a preclinical animal study and has not been tested in humans. The findings do not constitute medical advice. People with multiple sclerosis who take ozanimod or other medications should not change their diet without consulting their healthcare provider. Do not adjust medication doses based on this research. If you are considering a ketogenic diet while taking any prescription medication, discuss this with your doctor or neurologist first, as dietary changes may affect how your body processes medications. This article is for educational purposes only and should not replace professional medical guidance.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
