The #1 At-Home Test to Unlock Your Health (Glucose + Ketones + Lactate)
A comprehensive quick-guide to interpretation of these three critical markers.
If you are trying to improve your health with strategies that go beyond the basics of What Everyone Should Be Doing For Their Health, you need a way of knowing whether what you’re doing is working.
While producing self-rated health scores from the things you care most about is the best way to not get led astray by proxy markers, tracking glucose, ketones, and lactate can add some more objective math to your tracking and can often act as a leading indicator of a problem to come or can help you interpret the nature of a problem you are currently experiencing.
Energy Metabolism Governs Everything, and these are the three markers of energy metabolism you can measure at home to reflect the state of your mitochondrial energy production.
The primary reason to track all three is that
Glucose shows how efficiently your cells use carbs for energy.
Ketones show you how your body chooses to use fat or carbs for energy.
and lactate reveals whether your mitochondria are overstressed by the demands you are placing on them.
This protocol serves as a general framework for testing and interpreting these three markers. It provides you with details of how to get set up, best practices for testing, how to pick timepoints to test, normal ranges for all three markers, expected responses to eating meals, and then walks you through eight different patterns of change, giving you actionable solutions to each pattern you observe.
The Protocol Series
This is part of a series of protocols. See all of the protocols here:
Download the Protocol
Download the protocol here:
Optimize Your Mitochondria At Home With Glucose, Ketones, and Lactate
By Chris Masterjohn, PhD, 2025.
This protocol provides a general framework for interpreting glucose, ketones, and lactate when used for your own self-experiments, when using my overarching Optimization Framework, or when using any of my Protocols.
For the rationale behind testing glucose, ketones, and lactate, read the “Glucose, Ketones, and Lactate” section of Three Tests to Transform Your Health.
How to Get Setup and Start Testing
Obtain KetoMojo meter and strips, Novabiomedical Lactate Plus meter, Novabiomedical Lactate Plus strips, and alcohol pads. If you plan to do a LOT of testing, get extra KetoMojo strips, extra lactate strips, and extra 30g lancets.
When testing, wash your finger with soap, rinse well, then wipe with an alcohol pad, let air dry or lightly blot with a very clean tissue, then puncture your finger. Lightly massage your finger with soft lateral motion if needed but do not squeeze it. Wipe away the first 2-3 drops of blood with a very clean tissue, then test.
The meters can be finicky at first, especially the lactate meter. Put the edge of the strip at the surface of the drop and let it sip it up rather than shoving the strip into the drop. Make sure your drop of blood is big enough that the blood moves rapidly through the strip without stalling.
If you have trouble getting enough blood for this, try looking for the least calloused part of your finger. For many people, this is off to the side rather than the tip or the front face. If you cannot get enough blood to generate several large drops to wipe away prior to testing, you can try using a 28g lancet or a 21g lancet. The smaller the gauge the larger the needle, so you are sacrificing comfort and possibly risking more pain in order to get more blood. Ultimately, being able to wipe away two to three sizable drops before testing is necessary for accuracy.
When to Test
The most important time of day to test is soon after you wake up, while you are fasting, while you are still in the resting state and before you have gotten the chance to get riled up or do any meaningful activity.
Optionally, you can pick a second time to test if you find a meaningful reason to.
One reason to do so would be that you have a predictable daily cyclicality to a health problem you are trying to solve. For example, you always experience sleepiness a half hour after lunch or you always experience anxiety around sunset, or you always wake up at 3AM without being able to go back to sleep. If anything like this is true, measure at the point the problem is most activated, or at the time of day you expect the problem to be most activated.
Another reason to do so would be that your values are most abnormal at a certain time of day. The only way to know this is to test many time points during the day to sample what could be abnormal. Then, if you see a consistent pattern of abnormality at a repeating timepoint, use that as your second time point to test.
If you do an exploratory period of multiple tests throughout the day, reasonable time points to test apart from waking fasting would be just before each meal, one and two hours after each meal, and just before bed.
The best postprandial timepoint to use is one hour after you finish a meal. This is the most common time point reported in the literature postprandially, so it is easier to define what is “normal” compared to other time points.
You shouldn’t test during and after exercise unless you use external guidance about how to interpret exercise zones and lactate clearance in response to training regimens. To judge your general health, focus on the simpler interpretations of resting data here.
If you do a lot of testing, you will be doing repeated microdamage to your fingers. Try to rotate them as much as possible. If you can use each finger on a rotating basis, you can test daily but each finger will have ten days to recover between punctures.
Dealing With Variability
Since your finger prick will elicit a mix of capillary and venous blood alongside extracellular fluid and the contents of damaged cells, and since even the pure blood would be whole blood rather than plasma, you are going to get differences from a draw of venous plasma in the lab, and you are going to get more variability. You can limit this variability by following the guidelines above to remove two to three sizeable drops of blood before testing. You could also experiment with pricking your ear lobe instead of your finger.
However, if you are testing daily for weeks on each protocol regimen, as strongly advised in the Optimization Framework, the variability will average out over time, and by focusing on the averages you can avoid getting lost in the weeds.
One thing you should not do is second-guess abnormal data and retest it because you don’t trust it. Do any kind of validation experiments you want to assess the variability, but do them separately from your actual data collection. In order to minimize bias, you have to accept the data you generate without second-guessing and selectively repeating it.
How to Organize Your Data
Click here to download the Ultimate Optimization Spreadsheet.
Do not open it in Excel or any other desktop program. Immediately drag and drop it into Google Drive and double click to open it as a Google Sheet.
Otherwise, features will be lost.
If you are only testing waking, resting, fasted numbers, use the columns that are prelabeled as glucose, ketones, and lactate.
If you are measuring a second or third timepoint in the day, make a separate column for it. You can either rename the extracted variables and one of the self-rated variables as “afternoon glucose” and so on, or you can add additional variables as outlined at 18:43 in this video.
You do not want to mix and match different time points in the same column, because doing so will make it extremely messy to document protocol averages and rolling averages.
Normal Ranges
Cited values are in mg/dL for glucose and mmol/L for ketones and lactate. Online calculators allow you to interconvert these for glucose, ketones, and lactate.
Waking glucose should be under 90 and close to 80 mg/dL, with lower values being fine as long as you do not feel hangry, anxious, faint, or lose any neuromuscular function, energy, or cognitive capacity. Below 70 mg/dL can be suspected of being a problem, but often if your ketones rise to feed your brain adequately you can easily tolerate values lower than this.
Waking lactate should be 0.5-0.9 mmol/L.
Postprandial glucose should be under 140 at any time point and ideally close to 100 after one hour.
Postprandial lactate should be under 1.5 and ideally 0.9-1.2.
Ketones should be 0-0.2 mmol/L around the clock unless you are on a ketogenic diet or using MCT oil or large amounts of coconut. If you are on a ketogenic diet, you are probably not going to push much higher than 1.5 mmol/L, but if your diet is shifted sufficiently in favor of fat at the expense of both protein and carbohydrate, especially if you are also hypocaloric or if you are including MCT oil, it is possible for ketones to be pushed to 3-5 mmol/L and this is not necessarily abnormal. Ketones above 0.2 mmol/L on a non-ketogenic diet should be suspected as abnormal and ketones above 5 mmol/L on a strongly ketogenic diet should be suspected as a potential acidosis risk.
In response to a meal, especially in response to a carbohydrate-inclusive meal, glucose should go up, lactate should go up, and ketones should go down.
Interpreting Changes in These Numbers
If you are using one of my Protocols, the primary interpretation of how these numbers change is that if they move closer to the optimal range, what you are doing is working, and if they move further away from the optimal range, what you are doing is not working, or you have gone beyond your tolerance for a certain step. Consistent with the Optimization Framework, you are primarily relying on protocol step averages after you see in the visual charts that the rolling time-based averages have stabilized.
However, there are some notable change patterns that can help you further interpret these numbers even if you are using them without an existing protocol for exploratory purposes:
If glucose goes up and lactate goes down, this likely represents an impairment in glycolysis. You may be taking a medication that blocks glycolysis, such as aspirin, or you may have a dietary or metabolic toxin that blocks glycolysis, such as oxalate, or you may be deficient in a nutrient needed for glycolysis, such as niacin (vitamin B3) or potassium.
To manage oxalate, use my Oxalate Protocol.
The best way to increase niacin is to add one to three tablespoons of Sari Nutritional Yeast to anything that could use a cheesy flavor or to replace part of your regular meat with an organ blend such as US Wellness 75% Ground Beef With Heart, Kidney, and Liver. You can also add Niagen. If you do, you may use 300 milligrams a day for three to four days as a loading dose but then should start at a maintenance dose of ⅛ or ¼ of a capsule per day and titrate up slowly over time until the markers optimize. Any form of niacin should always be spread out as evenly across meals as is practical, and if you experience any adverse effects from it at doses that are helping to optimize your markers you can try matching it with an equal amount of trimethylglycine (TMG).
The best way to increase potassium is to increase the amount of potassium-rich foods in your diet, which include the lean portions of animal foods with juices consumed, lean portions of milk, egg whites (consume with yolks), tubers, legumes, fruits, and vegetables. Replacing refined grains with whole grains can help, but replacing grains altogether with foods from the list above helps much more. Replacing fat with those foods will help as well. Track your diet in Cronometer and get your food potassium up to at least 4.7 grams (4,700 milligrams) per day. If you use a supplement, review with your doctor that neither your medical conditions nor medications interfere with potassium excretion (explained in more detail in the Cheat Sheet); make sure you evenly distribute the supplement across meals, preferably taking it after a meal, or spreading it across the beginning and end of the meal; you can use citrate or gluconate, but if you supplement with grams per day you should start taking both citrate and gluconate and possibly other forms such as bicarbonate to avoid overdoing any one organic acid.
If glucose goes down and lactate goes up, this likely represents an improvement in glycolysis. If the lactate stays within the optimal range, the rise in lactate can be tolerated. Ideally, it self-resolves over a few days or a week with the lactate coming back down to where it was. If the lactate gets pushed out of the normal range or gets worse over time, this indicates that your respiratory chain is not keeping up with the improvement in glycolysis.
If the pyruvate dehydrogenase enzyme is limiting, the most likely solution is to improve your thiamin status. The best way to improve your thiamin status is to add one to three tablespoons of Sari Nutritional Yeast to anything that could use a cheesy flavor. If you need more, you can start with one to three droppers full of liquid thiamin if you digestively tolerate the glycerin, and then, if you still need more, move on to between a half capsule, slowly titrated up to as many as five capsules per day of TTFD. While using thiamin, watch carefully for a further increase in lactate and pull back to the dose that does not raise your lactate. If you cannot find a dose of thiamin that reverses the rise in lactate, you are most likely dealing with a respiratory chain impairment to be dealt with as described next.
If your respiratory chain is limited, this could be any one of 297 different genetic problems with a role for almost any of the essential nutrients. If you cannot resolve the rise in lactate out of the normal range by using the methods contained within the protocol you are using, Track Your Diet in Cronometer and make sure you are meeting all of my custom Nutrient Targets. If that does not work, run the Comprehensive Nutritional Screening and interpret it with the Cheat Sheet. If that does not work, run Mitome. If you are not resource-limited, you can run all of these at once and retest them as often as needed to arrive at the final resolution of the rise in lactate.
If lactate goes up without a change in glucose, by contrast, this indicates that you are stressing your pyruvate dehydrogenase or your or your respiratory chain with whatever you are doing. If you don’t have a solid empirical benefit to your health arising from your strategy, simply reverse it. If you do have an empirical benefit, try moderating the dose to one that does not raise lactate. If you cannot do so, you should explore alternative strategies to give you the same benefit without the rise in lactate, or revert to the ways to optimize your pyruvate dehydrogenase or respiratory chain in the two paragraphs directly preceding this one.
If glucose goes up without a change in lactate or ketones, this might indicate a blended effect of impaired glycolysis and respiratory chain function and you should moderate your strategy or reverse course as just described.
If glucose goes up and ketones go down this suggests that your carbohydrate supply is increasing, either because you are eating or absorbing more net carbs or because something is favoring greater glycogen breakdown. You should see if this self-resolves over several weeks, in which case you simply had to adjust to the greater glucose supply. However, if it does not show stable and linear improvement you should treat it as a case of overwhelmed glycolysis and should try the oxalate, niacin, and potassium strategies listed above. Otherwise you should engage in moderation or reversal of your strategy.
Ketones being abnormally high with normal glucose and lactate could be due to impaired utilization of ketones, in which case you should focus on suppressing fatty acid oxidation and ketogenesis with carbs and protein.
Abnormally high ketones could also be due to poor pyruvate carboxylase activity or poor respiratory chain function. This would be especially likely if you can demonstrate that eating carbs increases your ketones instead of decreasing them. This is called paradoxical postprandial ketogenesis. If you don’t have a severe problem, you may only be able to observe this after provoking it with an 18-hour fast and showing that ketones go up at the 15-minute mark. This would need to be shown after several repetitions compared to several observations of a control period (15 additional minutes of fasting) conducted in randomized order.
Pyruvate carboxylase activity can be improved with biotin or manganese, or by reducing oxalate levels.
To manage oxalate, use my Oxalate Protocol.
Manganese can be supplemented in 3-8 milligrams per day, but no one should supplement with manganese without first running the screening for manganese overload contained within my Manganese Detox Protocol.
Biotin can best be obtained as follows. First, make the base of your diet rich in grass-fed animal products, a diversity of fermented foods, and a large volume of fresh produce. Then, add one egg yolk equivalent for every 25 grams of non-collagen protein in your diet. Each egg yolk equivalent can be any of the following: one raw or cooked egg yolk with the white thrown in the trash; one whole egg boiled for at least four minutes; 1.5 fried eggs; 3.5 poached eggs; 8 grams of natto; 9 grams of chicken liver; or 36 grams of beef liver. If you need a supplement to obtain more, you can obtain low doses from Solgar 300 microgram tablets or from Life Extension 600 micrograms, which is a capsule that can be easily emptied into smaller doses. Higher doses can be obtained from Jarrow 5 milligrams, which is a cost-effective option, or Pure Encapsulations 8 milligrams, which is a brand that seems anecdotally to have the least likelihood of adverse response to low-level contaminants. Biotin should be slowly titrated up from the lowest dose you can find that lowers ketones without raising glucose or lactate, stabilizing at each dose before moving on, and increasing the dose until you hit the point of diminishing returns and then slightly pulling back.
If none of this works, you should assume the problem is in the respiratory chain, in which case you should use Cronometer, the Comprehensive Nutritional Screening, and Mitome as described in the second paragraph of the previous page.
If glucose and ketones go up together without a rise in lactate, this suggests either that your fatty acid oxidation is displacing your glucose utilization or that oxalate is accumulating and inhibiting glycolysis and simultaneously inhibiting the citric acid cycle. To address excess fatty acid oxidation try lowering your consumption of fat or your intake of riboflavin, pantothenic acid, and CoQ10. To manage oxalate, use my Oxalate Protocol.
If glucose, ketones, and lactate all rise together, you may have a blended problem of two or more of any of the above, but almost certainly are overburdening your respiratory chain. This strongly suggests you should reverse course, unless you are getting an empirical benefit, in which case you should fix your respiratory chain using Cronometer, the Comprehensive Nutritional Screening, and Mitome as described in the second paragraph of the previous page.
UPDATE LOG
In the potassium section, I added:
Replacing fat with those foods will help as well.
I also changed "blending" to "taking both" to avoid giving the impression they have to be actually mixed directly together.
I also added a paragraph on thiamin in handling elevated lactate.
This piece and your additional links are a generous treasure trove, thank you!
Here's my take: https://substack.com/home/post/p-171655230