Raising your GFR depends almost entirely on what is dragging it down. If the underlying cause is reversible, like poorly controlled blood sugar, high blood pressure, excess weight, or medication-related kidney stress, addressing that cause can slow or even partially reverse the decline. But if kidney tissue has been permanently scarred, you cannot regenerate it; the realistic goal shifts from raising the number to protecting what remains. The distinction between “fixable” and “protectable” shapes every step worth taking.
Why GFR Drops and What That Means for Recovery
Your GFR reflects how efficiently your kidneys filter blood, measured in milliliters per minute. A normal reading sits around 90 or above; below 60 raises a flag for chronic kidney disease (CKD). The number drops for two broad reasons. One is structural damage to the tiny filtering units in the kidney, caused by years of diabetes, uncontrolled hypertension, or other diseases. That damage is largely permanent. The other reason is functional strain: something is temporarily impairing blood flow to the kidneys, overworking the filters, or causing inflammation that hasn’t yet turned into scar tissue. Functional causes are where you have the most room to improve.
This matters because many people see a low GFR on lab work and assume their kidneys are failing, when in reality a treatable condition is suppressing the number. Conversely, some people chase a higher GFR without realizing that in certain situations, like early diabetes, an abnormally high GFR (called hyperfiltration) is itself a sign of damage in progress. The goal isn’t always to push the number higher. Sometimes slowing the rate of decline by even one or two points per year is a major win.
Get Blood Pressure Under Control
High blood pressure is one of the two biggest drivers of kidney decline, and tightening blood pressure control is one of the most evidence-backed ways to protect your GFR. A systematic review and meta-analysis of trials in people with CKD found that more intensive blood pressure lowering reduced the risk of end-stage kidney disease by about 21% compared with standard targets. For those who already had protein in their urine (proteinuria), the benefit was even stronger, cutting the risk of kidney failure by roughly 27%.1PubMed Central. Effects of intensive blood pressure lowering on the progression of chronic kidney disease: a systematic review and meta-analysis Interestingly, in patients without proteinuria, intensive lowering did not show a clear kidney benefit, which suggests that the protective effect depends on how much damage is already underway.
ACE inhibitors and ARBs are the first-line blood pressure medications for kidney protection because they reduce pressure inside the glomeruli, the kidney’s tiny filters, in addition to lowering systemic blood pressure. Your doctor may also add a newer class of drug called a nonsteroidal mineralocorticoid receptor antagonist (MRA), such as finerenone, which has been shown in clinical trials to reduce protein leakage in the urine and slow GFR decline over time in people with diabetic kidney disease.2PubMed Central. Dose-Exposure-Response Analysis of the Nonsteroidal Mineralocorticoid Receptor Antagonist Finerenone on UACR and eGFR: An Analysis from FIDELIO-DKD
Manage Blood Sugar If You Have Diabetes
Diabetes is the single most common cause of CKD worldwide, and blood sugar control directly influences kidney trajectory. In diabetic patients, high glucose levels cause the kidneys to overwork, filtering at an unsustainably high rate. Over time this hyperfiltration damages the filters and GFR begins to fall. Tightening glucose control reduces that hyperfiltration, which paradoxically causes a short-term dip in GFR before stabilizing kidney function over the longer term.3PubMed Central. Effect of glycaemic control on glomerular filtration rate in Diabetes Mellitus patients This initial dip can be alarming if you’re watching your numbers closely, but it reflects a reduction in the harmful hyperfiltration that drives diabetic nephropathy.
A class of diabetes medications called SGLT2 inhibitors (drugs like empagliflozin, dapagliflozin, and canagliflozin) has become a cornerstone of kidney protection. These drugs work by reducing pressure inside the kidney filters through a mechanism that operates independently of blood sugar control, which is why they are now prescribed to people with CKD who don’t even have diabetes.4PubMed Central. Prescribing SGLT2 Inhibitors in Patients With CKD: Expanding Indications and Practical Considerations A meta-analysis found that SGLT2 inhibitors slowed the chronic rate of GFR decline by about 1.9 mL/min per year compared to placebo, reduced the risk of end-stage kidney disease by 30%, and cut the risk of serum creatinine doubling by a third.5PubMed Central. Effectiveness of SGLT2 inhibitors in slowing chronic kidney disease progression and reducing mortality: a meta-analysis
Like blood sugar control itself, SGLT2 inhibitors typically cause an initial, functional dip in GFR during the first few weeks. This isn’t kidney damage. It is the drug reducing the excess pressure inside the filters, a pattern that leads to better long-term preservation.6PubMed Central. Renal effects of SGLT2 inhibitors: an update One retrospective study found that people whose kidneys were declining fastest before starting the drug saw the greatest improvement in their GFR trajectory afterward.7PubMed. Larger Degree of Renal Function Decline in Chronic Kidney Disease Is a Favorable Factor for the Attenuation of eGFR Slope Worsening by SGLT2 Inhibitors: A Retrospective Observational Study
Dietary Changes That Actually Help
Diet is one of the most actionable areas for kidney protection, but the advice can feel contradictory depending on where you read. Here’s what the research supports.
Protein Intake
High protein intake can increase pressure inside the kidney filters and lead to hyperfiltration and protein leakage.8PubMed Central. The Effects of High-Protein Diets on Kidney Health and Longevity For people who already have CKD, moderately reducing protein may help. A secondary analysis of the landmark MDRD trial found that each modest decrease in protein intake was associated with a slower rate of GFR decline and roughly half the risk of kidney failure or death.9PubMed Central. Dietary Protein Intake and Chronic Kidney Disease That said, in people with healthy kidneys, the picture is less clear. A large community study found no association between protein intake and GFR change in older adults with normal kidney function, whether the protein came from animal or vegetable sources.10PubMed Central. Dietary Protein Intake and Change in Estimated GFR in the Cardiovascular Health Study The practical takeaway: if you have CKD, work with a dietitian on a moderate-protein plan. If your kidneys are fine, you probably don’t need to worry about your steak habit.
Shift Toward Plant-Based Foods
A growing body of evidence suggests that plant-heavy diets produce a lower acid load in the body, which appears to benefit the kidneys. Research from the ARIC cohort found that people eating more plant-based diets had lower markers of dietary acid load.11PubMed Central. Plant-based diets for kidney disease prevention and treatment A systematic review of trials in CKD patients found that the two largest randomized studies both reported a statistically significant increase in GFR after switching to a vegetarian diet.12PubMed Central. The impact of a vegetarian diet on chronic kidney disease (CKD) progression – a systematic review One reason may be fiber: dietary fiber feeds gut bacteria that help reduce uremic toxins, inflammatory compounds that accumulate in CKD and further damage the kidneys.13PubMed Central. The Role of Dietary Fiber and Gut Microbiome Modulation in Progression of Chronic Kidney Disease
You don’t have to go fully vegetarian. Simply eating more fruits, vegetables, and whole grains while cutting back on processed meat and animal protein can move you in the right direction. In one trial of people with stage 4 CKD, adding fruits and vegetables to correct metabolic acidosis produced kidney-protective benefits comparable to taking sodium bicarbonate supplements, without increasing potassium to dangerous levels.14PubMed Central. A comparison of treating metabolic acidosis in CKD stage 4 hypertensive kidney disease with fruits and vegetables or sodium bicarbonate
Cut Back on Salt
Excess sodium raises blood pressure and increases the workload on your kidneys. A randomized controlled trial of CKD patients found that the group eating a standard diet lost about 3 mL/min of GFR over three months, while the low-salt group maintained their function significantly better.15PubMed Central. Effect of a Low Salt Diet on the Progression of Chronic Kidney Disease: A Prospective, Open-Label, Randomized Controlled Trial Aiming for under 2,000 mg of sodium per day is a commonly recommended target for people with kidney concerns.
Limit Phosphorus
As kidneys lose function, they struggle to clear phosphorus, and elevated phosphorus drives a hormonal cascade that further damages the kidneys and blood vessels. A study in patients with early-stage CKD (stages 1-2) found that restricting dietary phosphorus improved GFR, lowered the damaging hormone FGF-23, and raised levels of the protective protein Klotho.16PubMed Central. Effect of Dietary Phosphorous Restriction on Fibroblast Growth Factor 2-23 and sKlotho Levels in Patients with Stages 1-2 Chronic Kidney Disease The biggest sources of hidden phosphorus are processed foods and soft drinks, where phosphate additives are absorbed much more efficiently than the phosphorus found naturally in whole foods.
Address Metabolic Acidosis
CKD often causes acid to build up in the blood because the kidneys can no longer excrete it efficiently. This low-grade acidosis accelerates kidney decline and muscle wasting. A meta-analysis of trials using oral sodium bicarbonate (baking soda supplements, essentially) found that treatment slowed the loss of GFR compared to controls, alongside a meaningful rise in blood bicarbonate levels.17PubMed Central. The Effects of Oral Sodium Bicarbonate on Renal Function and Cardiovascular Risk in Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis This is typically a doctor-supervised treatment, since the extra sodium can raise blood pressure in some people.
Lifestyle Steps Beyond Diet
Lose Weight If You Carry Excess
Obesity forces the kidneys to filter at a higher rate to support a larger body mass, which over time leads to the same kind of hyperfiltration damage seen in diabetes. A lifestyle intervention study of obese CKD patients found that after just two months, those who reached their weight-loss target saw their GFR jump from about 76 to 105 mL/min, with significant drops in creatinine and proteinuria.18Journal of Renal Nutrition. Effects of Dietary Management and Physical Exercise on Weight Loss in Obese Patients With Chronic Kidney Disease That increase reflected the reversal of hyperfiltration-related strain. In people whose kidneys were already impaired (GFR under 90), weight loss after bariatric surgery showed a trend of GFR improvement from about 69 to 79 mL/min.19PubMed. Effect of weight loss after bariatric surgery on kidney function in a multiethnic Asian population
Drink Enough Water
Staying well hydrated keeps your kidneys flushing waste efficiently. A community-based cohort study found a clear dose-response relationship: as daily urine volume went up, the annual rate of GFR decline went down. People producing three or more liters of urine per day were about half as likely to experience rapid kidney decline compared to those producing one to two liters.20PubMed Central. Urine volume and change in estimated GFR in a community-based cohort study That doesn’t mean you should force down water until you feel sick. Drinking enough that your urine stays a pale straw color throughout the day is a reasonable practical guide, though people with heart failure or advanced CKD may need to follow fluid restrictions set by their doctor.
Quit Smoking
Smoking accelerates kidney damage through multiple pathways: it constricts blood vessels, raises blood pressure, and directly injures the tiny vessels in the kidneys. In a Japanese cohort study, people who continued smoking had about 2.5 times the odds of developing proteinuria compared to non-smokers, while those who quit saw their risk drop to statistically indistinguishable from never-smokers.21PubMed Central. The effects of continuing and discontinuing smoking on the development of chronic kidney disease (CKD) in the healthy middle-aged working population in Japan In people with type 2 diabetes, smokers lost kidney function faster than non-smokers or quitters, and quitting was shown to slow the progression of early diabetic nephropathy even when blood pressure was well controlled with medication.22PubMed. Cigarette smoking exacerbates and its cessation ameliorates renal injury in type 2 diabetes
Stop What’s Hurting Your Kidneys
Sometimes the fastest way to improve kidney function is to remove whatever is actively harming it. NSAIDs like ibuprofen and naproxen are among the most commonly overlooked culprits. These drugs work by blocking prostaglandins that maintain blood flow to the kidneys, and regular use is associated with a substantially elevated risk of both acute kidney injury and chronic kidney disease.23PubMed Central. Kidney damage from nonsteroidal anti-inflammatory drugs-Myth or truth? Review of selected literature One review estimated a 50% to 70% increased risk of kidney problems with regular NSAID use, including both older drugs and newer selective COX-2 inhibitors.24South Asian Research Journal of Biology and Applied Biosciences. NSAIDs and Kidney Health: A Review of the Silent Threat to Renal Function If you have CKD or are at risk for it, talk to your doctor about switching to acetaminophen or other alternatives for pain management.
Other substances to be cautious about include certain herbal supplements (some contain compounds toxic to the kidneys), high-dose vitamin C (which can form kidney-damaging oxalate), and proton pump inhibitors used long-term. Cholesterol management also matters: although definitive trials are lacking, the collective evidence suggests that treating dyslipidemia with statins is associated with less decline in kidney function over time.25PubMed. The role of statins in chronic kidney disease
When Your GFR Number Is Misleading
Before you panic about a low GFR reading, it’s worth understanding that the standard blood test can be wrong. The most common GFR estimate is calculated from serum creatinine, a waste product of muscle metabolism. Anything that raises creatinine levels independent of kidney function will make your estimated GFR look artificially low.
The most frequent offender is creatine supplementation. Creatine, widely used for exercise performance, breaks down into creatinine in the body. A meta-analysis found that creatine supplementation causes a small but statistically significant increase in serum creatinine, though this increase is a predictable byproduct of creatine metabolism rather than a sign of kidney damage. Pooled data from five studies showed no significant change in actual GFR after creatine supplementation.26PubMed Central. Effect of creatine supplementation on kidney function: a systematic review and meta-analysis So if you take creatine and your doctor flags a low eGFR, the reading may simply reflect extra creatinine in your blood rather than impaired filtering.27PubMed. The effect of creatine intake on renal function
Muscle mass, diet, and physical activity can also nudge creatinine-based estimates in misleading directions. A very muscular person may show a falsely low eGFR because they produce more creatinine, while someone who has lost significant muscle mass (common in older adults and people with advanced CKD) may get a falsely reassuring reading.28Quality in Sport. Diagnostic Pitfalls, Creatine Supplementation, Physical Activity, and Kidney Function Assessment in Non-Dialysis Chronic Kidney Disease: A Narrative Review
If you suspect your creatinine-based eGFR is inaccurate, ask your doctor about a cystatin C test. Cystatin C is a small protein produced at a steady rate by all cells and filtered by the kidneys. Unlike creatinine, it is not significantly affected by muscle mass, diet, or supplements. A large study across multiple populations found that using cystatin C instead of, or alongside, creatinine improved risk classification for death and end-stage kidney disease.29PubMed Central. Cystatin C versus creatinine in determining risk based on kidney function Combining both markers gives the most accurate estimate of true GFR.30PubMed Central. Estimating GFR using Serum Cystatin C Alone and in Combination with Serum Creatinine: A Pooled Analysis of 3418 Individuals with CKD
The Confusing Dip That Is Actually Good News
One pattern that trips people up is the initial GFR drop that occurs after starting certain protective medications. ACE inhibitors, ARBs, and SGLT2 inhibitors all reduce pressure inside the kidney filters, which shows up as a short-term decline in GFR on blood work. If you’ve just started one of these drugs and your GFR dips by a few points, that is usually the medication doing its job, not your kidneys getting worse. SGLT2 inhibitors cause an immediate functional reduction in GFR that then stabilizes, and the long-term trajectory is better than it would be without the drug.6PubMed Central. Renal effects of SGLT2 inhibitors: an update Doctors generally expect to see a drop of a few points in the first weeks and will only intervene if the decline is steep or doesn’t stabilize.
The same logic applies to improved blood sugar control in diabetics. Bringing glucose levels down reduces hyperfiltration, and hyperfiltration makes GFR look deceptively high. When you remove that artificial boost, GFR appears to fall, but the kidneys are actually under less strain.3PubMed Central. Effect of glycaemic control on glomerular filtration rate in Diabetes Mellitus patients Understanding this pattern prevents the common mistake of stopping a beneficial medication because the short-term lab numbers look scary.
What Exercise Can and Cannot Do
Regular physical activity helps kidney function indirectly by improving blood pressure, blood sugar, weight, and cardiovascular health, all of which reduce the load on your kidneys. In the weight-loss intervention study mentioned earlier, the combination of dietary changes and physical exercise produced significant improvements in multiple kidney markers within two months.18Journal of Renal Nutrition. Effects of Dietary Management and Physical Exercise on Weight Loss in Obese Patients With Chronic Kidney Disease There is no strong evidence that exercise alone raises GFR in someone whose kidneys are otherwise healthy and whose weight, blood pressure, and blood sugar are normal. The benefit comes from the downstream improvements in the conditions that drive kidney damage.
One caveat for very intense exercise: a hard workout can temporarily raise serum creatinine simply because of increased muscle breakdown, which can temporarily lower your eGFR reading the next morning. If you are monitoring kidney function, avoid strenuous exercise for 24 to 48 hours before a blood draw to get the most accurate snapshot.