Starting a low-carb or keto diet with high blood pressure


So you have high blood pressure and you want to try a low-carb or keto diet? Congratulations! It may be the most effective thing for lowering your blood pressure naturally.1 In some cases it may even normalize your blood pressure completely.2

However, there are two minor potential issues you may need to be aware of before you start.

1. Blood-pressure medication

If you’re on blood-pressure medication and start a low-carb diet, there’s a risk of the diet working too well! That could mean you experience low blood pressure. Yes, it’s true. You may become too healthy for your current dosage of medication.3

This blood-pressure lowering effect with low carb nutrition can happen within days, but it may also take months or even a year to reach full effect.4

If you feel symptoms of low blood pressure, such as feeling weak, tired or dizzy, you should immediately check your blood pressure. If it’s low, e.g. below 120/80, you should contact your doctor to discuss if lowering or stopping your medication is appropriate for you.

This is something most doctors should be able to handle. But if you need to find a doctor with good knowledge about the handling of medication on a low-carb diet, check out our low-carb doctors map and directory.

We also have a detailed guide about blood pressure drugs.

2. Salt and bouillon Cup of bouillon

When starting a low-carb diet we often recommend getting extra fluid and salt, perhaps in the form of bouillon – especially during the first two weeks. The reason is to minimize early side effects that can otherwise be troublesome when starting low carb, e.g. headache.

You should only take this bouillon if your blood pressure is well controlled, as for some it may increase blood pressure marginally.5

If your blood pressure is high despite medication you should not take extra salt or bouillon. Doing so could raise the blood pressure even higher, and it is not wise to risk that.

The good news is that any side effects will usually pass within days to a couple weeks as your body switches from using glucose to using fat as its main fuel.6

Learn more

How to normalize your blood pressure

Find a low-carb doctor

A low-carb diet for beginners

A keto diet for beginners

Low carb for doctors

Are you a doctor or do you know one? Here’s our low carb for doctors resource, with information on how to safely handle medications on a low-carb diet:

Low carb for doctors

Disclaimer: Discuss any changes in medication and relevant lifestyle changes with your doctor. Full disclaimer

Starting low carb or keto with high blood pressure - the evidence

This guide is written by Dr. Andreas Eenfeldt, MD and was last updated on June 17, 2022. It was medically reviewed by Dr. Michael Tamber, MD on March 8, 2022.

The guide contains scientific references. You can find these in the notes throughout the text, and click the links to read the peer-reviewed scientific papers. When appropriate we include a grading of the strength of the evidence, with a link to our policy on this. Our evidence-based guides are updated at least once per year to reflect and reference the latest science on the topic.

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  1. The research to date shows that blood pressure often declines in people following carbohydrate-restricted diets:

    Obesity Reviews 2012: Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors [strong evidence]

    Archives of Internal Medicine 2010: A randomized trial of a low-carbohydrate diet vs orlistat plus a low-fat diet for weight loss [moderate evidence]

    International Journal of Environmental research and Public Health 2019: Substantial and Sustained Improvements in Blood Pressure, Weight and Lipid Profiles from a Carbohydrate Restricted Diet: An Observational Study of Insulin Resistant Patients in Primary Care [observational study, weak evidence]

    Cardiovascular Diabetology 2018: Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study [weak evidence]

    South African Journal of Critical Care 2013: Low-carbohydrate and high-fat intake can manage obesity and associated conditions: occasional survey [very weak evidence]

  2. In a small study, people with metabolic syndrome who followed a ketogenic diet for 12 weeks experienced significant reductions in blood pressure, going from an average of 141/89 to 123/76, along with weight loss and other health improvements. In fact, by the end of the study, many of them no longer met the criteria for a diagnosis of metabolic syndrome:

    Journal of Medicinal Food 2011: A pilot study of the Spanish ketogenic Mediterranean diet: an effective therapy for the metabolic syndrome [non-randomized study; weak evidence]

  3. In one very-low-carb diet study, researchers had to discontinue blood pressure medications in 11% of participants due to reductions in blood pressure:

    Cardiovascular Diabetology 2018: Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study [weak evidence]

  4. This is based on consistent clinical experience of low-carb practitioners. [weak evidence]

  5. This effect occurs in individuals with “salt-sensitive” hypertension, who respond to higher salt intakes with an increase in blood pressure:

    Current Opinion in Nephrology and Hypertension 2012: Mechanisms and consequences of salt sensitivity and dietary salt intake [overview article; ungraded]

  6. This is based on clinical experience of low-carb practitioners and was unanimously agreed upon by our low-carb expert panel. You can learn more about our panel here [weak evidence]

    It is also supported by this small randomized study

    Nutrition X 2019: Effects of differing levels of carbohydrate restriction on the achievement of nutritional ketosis, mood, and symptoms of carbohydrate withdrawal in healthy adults: A randomized clinical trial [moderate evidence]