A little over a year ago, Craig wrote a post on what lab tests to get to measure your metabolic health. Although the original post still has great information, including how to request tests from your doctor, we figured it was about time to make an update, in order to provide information on which tests we think still remain relevant, which tests are worth testing frequently, new tests we’ve come across in the past year (or tests that have gained more relevancy over the past year), as well as make it a bit easier to pick tests based on specific needs (e.g. budget, level of data desired, etc). Hopefully this post will help with that, and make picking out tests, and tracking your health, a bit easier.
The tests are divided into “sets”, organized by what how much data you’re trying to gather, as well as by cost for those paying out of pocket (cost will vary by which provider you order through, but the tests which provide important information for the least amount of cost are in the first sets, while more niche tests are in the last sets). You can also click on the test names to get a brief description, and possible confounders for the results if we know of any.
The “Basics” Set
These tests are good to get every single time. This list is for those of you who are just looking for the bare basics and aren’t too interested in the more niche markers, or you’re paying out of pocket and you’re on a budget.CBC With Differential/Platelet
This is actually a pack of over a dozen different measures, which can help verify or hint at issues like anemia, or infection, among others. If self experimenting this can be helpful to verify possible illness wasn’t a confounder for your results.
Comprehensive Metabolic Panel (14)
This is another pack, but this one focuses on electrolytes (e.g. sodium, and potassium levels in the blood), liver enzymes (ALT, AST), and some measures of kidney function. Some of these can be impacted by simple issues (high BUN from dehydration, high ALT/AST from exercise prior to the test) so try to make sure you keep those in mind when getting the test done to make sure you don’t accidentally influence the results.
High Sensitivity C-Reactive Protein. hs-CRP is a measure of inflammation – however it’s worth noting that it tends to react pretty strongly to even small sources. Recent injury, intensive exercise prior to the test, infection, or issues related to diet or environment. Regardless, it’s worth it as a “look closer” marker, and can help suss out issues that weren’t noticed before.
Short for Hemoglobin A1c. A measure of glycated hemoglobin (hemoglobin is a protein found in red blood cells), generally used for diagnosing pre-diabetes or diabetes. Good to keep an eye on!
Far before blood glucose dysregulation appears, some research suggests that hyperinsulinemia can be the canary in the coal mine for many health issues and can be a risk factor for issues ranging from diabetes to PCOS to psoriasis. Far beyond its use in energy metabolism, insulin can also have an effect on immune cells, and more as described in this post.
A collection of (generally) four tests, including Total Cholesterol, HDL-C, LDL-C, and triglycerides. You can also calculate remnant cholesterol from your lipid panel, as well as using it to determine if you are a so-called Lean Mass Hyper-responder. Common things people look for are high triglycerides, and low HDL. A note should be made that – triglcerides in particular – are very dynamic and so a normal fluctuation of roughly 20-30% for triglycerides is not unusual. HDL tends to be relatively more stable, although it can be affected by dietary fat intake, sudden drops in HDL-C (especially with no change in diet) are unusual.
“Digging A Little Deeper” Set
Perhaps you’re just interested in markers beyond the basics, you’re trying to pinpoint a problem, or you’re just looking to get a broader look at the bigger picture – this is the list for you! Combine this with the “basics” list.
Ferritin is a protein involved in iron storage, and testing it can help determine if one has anemia (if paired with other results), but it is also an acute phase reactant and can be paired with hs-CRP in order to help spot ongoing or acute inflammation.
GGT stands for Gamma-Glutamyl Transferase and is a type of enzyme found in multiple types of tissues, but is mostly found in the liver. It can be used to help detect possible liver damage, or other issues.
Uric Acid, Serum
Those with metabolic syndrome tend to have higher levels of uric acid in the blood, thus it can be used as an additional marker of metabolic health – high levels can also lead to gout (a type of arthritis affecting the joints). However, there appears to be a transient rise in uric acid during the adaption phase of a ketogenic diet, so any testing in that time period may be inaccurate in regards to this marker. Higher levels should resolve once adaption is complete.
Insulin and C-Peptide, Serum (instead of insulin from the basics set)
Includes an insulin test, as well as C-Peptide. C-Peptide is released when insulin is produced, and thus is another measure of insulin production in the body. It can be slightly more reliable of an indicator of insulin secretion, however, as it has a slightly longer residence time in the blood than insulin does.
This provides a bit more information than a standard lipid panel. Along with Total Cholesterol, HDL-C, LDL-C, and triglycerides, it also includes information like LDL-P (also referred to as “particle number”), small LDL, and HDL-P.
Lipoprotein(a) has been getting more publicity lately, and is generally considered a lesser known cardiovascular risk marker. Levels are generally considered to be mostly genetic, however recent experiments have demonstrated this may not necessarily be true – and high values could be the result of genetic factors, dietary factors, as well as inflammatory signalling. A more in-depth review on lipoprotein(a) can be found here.
A cardiovascular risk marker, and possible marker of oxidative stress, occasionally factored in when looking at lipoprotein(a) levels. Anecdotally it seems low carbers have slightly higher levels, but well below thresholds mentioned in studies using it as a marker of cardiovascular disease risk alongside lipoprotein(a)
“Citizen Scientist / Establishing Extensive Baseline” Set
Planning to do some heavy duty experimenting of your own, or planning to replicate one that’s already been done? About to make a major lifestyle change, and want to capture an extensive baseline? Got a Christmas bonus, and the thought of plentiful data tickles your fancy? This is the list for you! Combine with previous two lists.
Higher levels are possibly associated with a higher risk of stroke, heart disease, and other health ills. Higher levels could be due to deficiencies in B vitamins (like B12 or folate), which could be due to inadequate intake or issues properly absorbing the vitamins, such as those with mutations in the MTHFR gene, although there are other possible causes as well. More context can be provided by also testing B12 and folate levels.
Fatty Acids, Free (Nonester)
A measure of free fatty acids (e.g. fat-based energy) in the blood – another way to tune in to energy metabolism.
Vitamin B12 and Folate
Vitamins used for processes like mood regulation, creation of healthy red blood cells, etc. Deficiencies can lead to anemia, birth defects, and other issues.
Tumor Necrosis Factor Alpha. A pro-inflammatory cytokine (e.g. a protein used to signal inflammation). Another inflammatory marker.
Insulin-Like Growth Factor-1; a growth hormone. Chronically high levels (along with hyperinsulinemia) are associated with increased risk of cancer, as discussed here. Levels may also change during multi-day fasting, exercise, etc.
“Thyroid Check-in” Set
Want to check in on your thyroid health? Is your doctor not sure what to test for, or only tested TSH without looking further? Here are some other tests you can order, or suggest, that may provide more useful and in-depth information about how everything is working. Combine with any other list(s).
A thyroid hormone, which helps control metabolism. Low levels could be indicative of a condition called hypothyroid (marked by fatigue, cold extremities, sensitivity to cold, and others), but it’s also worth noting that those following a low carb, ketogenic, or carnivorous diet may have lower levels of T3 and yet be asymptomatic. This has been argued to be an adaptive mechanism, and may not necessarily be hypothyroid in-and-of-itself.
Reverse T3, Serum
Reverse T3 is essentially an inactive mirror version of T3. It competes for the same receptors, and thus inhibits T3 function. In other words, it helps to keep T3 in balance – where too much T3 can result in symptoms of hypothyroid while too little can result in symptoms of hyperthyroid (even if TSH and T4 are normal). It can help get a better over all picture of thyroid health, and the context of the other numbers.
Thyroxine (or T4) is another thyroid hormone, and is also used to regulate metabolism. Low or high levels can be indications of hypo- or hyperthyroidism as is true of T3.
Combined with T3 uptake, a free T4 index can be provided, which is used to evaluate thyroid function.
Thyroid Stimulating Hormone – it’s actually a hormone made by the pituitary gland, which stimulates the thyroid to produce thyroid hormones. Often this is ordered alone, but comes with the downside of the lack of context given by the other measures on the list. One can have normal TSH, but still be hypo- or hyperthyroid, thus the importance of verifying the other measures as well.
The most generally expensive or unwieldy tests belong here. Only for the most overachieving testers with money to burn, and questions to answer.
The counter to insulin. While insulin is generally used to signal building and storage, glucagon generally does the opposite. In Ben Bikman’s presentation from Low Carb Breckenridge 2018, he argued that insulin response should be taken into context alongside glucagon’s response as well (such as the insulin response to dietary protein intake).
Another pro-inflammatory cytokine – can be combined with others for redundancy and validation of higher levels of inflammation. This is on the overachiever set, because it’s generally more expensive than other options.
Where to Get Them
Depending on how open your doctor is to getting additional testing done, you could always work with them to order some of the tests, especially if it’s the items from the “Basics” set. However, the chance of them ordering high frequency tests (for experiments, etc), or some of the more obscure tests like IGF-1, is less likely. Dave and I are currently beta testing a way to get inexpensive labs available for those in the states, but in the mean time most people I’ve seen choose to go through third parties to order the tests, such as Request a Test and Ulta Lab Tests. These write up a lab order which you get fulfilled through a private lab, such as Quest or Labcorp. (This will obviously differ by country, however, so if anyone knows of different providers in other countries, feel free to leave them in the comments if you know they’re reliable.)