A ketogenic diet can lower blood pressure, often by a meaningful amount. In studies of people with overweight or obesity, systolic blood pressure (the top number) dropped by roughly 10 mmHg within the first three months, with smaller reductions in diastolic pressure (the bottom number). That level of improvement is comparable to what some blood pressure medications achieve, though results vary depending on your starting weight, metabolic health, and how strictly you follow the diet.
How Much Blood Pressure Drops on Keto
The most consistent finding across studies is a systolic reduction in the range of 9 to 11 mmHg. In a large observational study of 377 adults with overweight or obesity, a very low-carbohydrate ketogenic diet produced a 10.5 mmHg drop in systolic pressure and a 2.2 mmHg drop in diastolic pressure within three months. A separate primary care study tracking patients for an average of two years found a mean systolic reduction of 10.9 mmHg and a diastolic drop of 6.3 mmHg.
For people with type 2 diabetes specifically, a meta-analysis published in Nature found systolic pressure fell by about 4.3 mmHg and diastolic by about 5.1 mmHg. The slightly smaller systolic drop in this group may reflect the complexity of managing blood sugar and blood pressure simultaneously, but the diastolic improvement was notably strong.
Keto vs. the DASH Diet
The DASH diet (Dietary Approaches to Stop Hypertension) has long been the standard dietary recommendation for blood pressure from the American Heart Association. It emphasizes fruits, vegetables, whole grains, and low-fat dairy while limiting sodium. A head-to-head randomized trial published in the Annals of Family Medicine tested a very low-carb diet against DASH in adults who had hypertension along with prediabetes or type 2 diabetes.
The very low-carb group saw systolic pressure drop by 9.8 mmHg over four months, compared to 5.2 mmHg in the DASH group. That 4.6 mmHg difference was statistically significant, and the pattern held in both the full analysis and among people who completed the entire trial. This is a single study, and the 2025 AHA/ACC guidelines still position DASH as the first-line dietary approach for hypertension, noting that low-carbohydrate diets have been shown to lower blood pressure but “less effectively than the DASH eating plan” across the broader body of evidence. Still, for people who also need to manage blood sugar and weight, the combination of benefits from a very low-carb approach may be worth discussing with a provider.
When You Can Expect Results
Blood pressure changes on keto tend to follow a predictable timeline. The earliest measurable drops appear within about six weeks. In one randomized controlled trial, both systolic and diastolic pressure decreased significantly by the six-week mark. The bulk of improvement seems to happen in the first 12 weeks. In the 377-person observational study, blood pressure dropped substantially in the first three months, then plateaued for the remaining nine months of follow-up. Weight loss followed the same pattern: most of it happened early, then stabilized.
Longer-term data is encouraging but limited. The primary care study that tracked patients for a median of 24 months found that blood pressure reductions were sustained over that period. The key variable appears to be whether you stick with the diet. In the 12-month study, 66 of the original 377 participants dropped out, and none left for clinical reasons, but maintaining a very low-carb diet for years is difficult for many people.
Why Keto Affects Blood Pressure
Several things happen simultaneously when you cut carbohydrates drastically. The most immediate effect involves insulin and sodium. When insulin levels are high (common in people with insulin resistance or type 2 diabetes), your kidneys hold onto sodium, which increases fluid volume in your blood vessels and raises pressure. On a ketogenic diet, insulin levels fall, and your kidneys begin releasing more sodium and water. This is why people often lose several pounds of water weight in the first week or two of keto, and it’s also why blood pressure can start dropping relatively quickly.
Weight loss amplifies the effect. Losing excess body fat reduces the physical strain on your cardiovascular system and improves how your blood vessels respond to changes in blood flow. In the type 2 diabetes meta-analysis, the average weight loss was 8.66 kg (about 19 pounds) with a 9 cm reduction in waist circumference. The researchers noted that blood pressure improvements likely benefited from this weight loss directly.
Electrolytes Need Attention
The same mechanism that helps lower blood pressure, your kidneys flushing sodium, can create problems if you’re not careful. In the early weeks of keto, rapid sodium and fluid loss can cause headaches, fatigue, and dizziness, sometimes called “keto flu.” If you’re already on blood pressure medication, this sodium loss combined with your medication could push your blood pressure too low.
Potassium matters just as much. Sodium and potassium work together to regulate fluid balance and blood vessel tension. Consuming too much sodium relative to potassium raises blood pressure, while increasing potassium intake helps bring it down. Many ketogenic foods are good sources of potassium (avocados, leafy greens, nuts, salmon), but if your version of keto leans heavily on cheese, bacon, and processed meats, you could end up with a sodium-heavy, potassium-poor pattern that partially cancels out the diet’s benefits.
Risks Worth Knowing About
The most immediate concern is for people already taking blood pressure or diabetes medications. Because keto can lower blood pressure and blood sugar quickly, sometimes within the first few days, medication doses may need to be reduced to prevent blood pressure from dropping too low or blood sugar from crashing. This is not a theoretical risk. Symptoms of blood pressure that’s too low include dizziness when standing, lightheadedness, and fainting.
Beyond blood pressure, the ketogenic diet carries some broader health considerations. It has been associated with higher LDL cholesterol in some people, kidney stones, constipation, and nutrient gaps that come from cutting out entire food groups. These don’t cancel out the blood pressure benefit, but they mean keto isn’t automatically a net positive for cardiovascular health in every person. If you have kidney disease, heart disease, or are on multiple medications, the decision to start keto should involve your care team so medication adjustments can happen safely and quickly.
Who Benefits Most
The strongest blood pressure results show up in people who have the most metabolic dysfunction to begin with: those with obesity, insulin resistance, prediabetes, or type 2 diabetes. If you carry excess weight around your midsection and your blood pressure is already elevated, you’re the profile most likely to see a meaningful drop. The randomized trial comparing keto to DASH specifically enrolled people with hypertension plus prediabetes or diabetes, and the very low-carb group outperformed DASH in that population.
If your blood pressure is only mildly elevated and you’re at a healthy weight, the effect will likely be smaller, and other dietary patterns like DASH or Mediterranean eating may offer a better balance of cardiovascular benefits without the restrictiveness of keto. The 2025 AHA/ACC guidelines recommend heart-healthy eating patterns broadly, with DASH as the most evidence-backed option, while acknowledging that low-carbohydrate diets do reduce blood pressure compared to various control diets.