All Guides
Lab Testing, Explained
Evidence-based guides across every major testing category. No jargon, no sales pitch — just the science.
Looking up a specific term? See the glossary →
Biological Age Tests: Epigenetic Clocks, Telomere Length, and Glycan Age
Horvath's clock, GrimAge, TELOS — biological age tests claim to measure how fast you're aging. Here is what the science supports.
Gut Microbiome Testing Explained: 16S rRNA vs. Shotgun Sequencing
Viome, GutBio, Microbiome Labs — the field is crowded. This guide explains the two main sequencing methods and what each can tell you.
Continuous Glucose Monitors for Non-Diabetics: What the Data Actually Means
Abbott Libre, Dexcom — CGMs are now sold direct-to-consumer. This guide covers what they measure, who benefits, and the limitations.
Thyroid Function Tests Explained: TSH, T4, T3, and Antibodies
TSH, Free T4, Free T3, TPO, TgAb — what each test measures and why "subclinical" thyroid dysfunction matters.
Understanding Your Lipid Panel: LDL, HDL, Triglycerides, and Beyond
Cholesterol is more nuanced than LDL vs. HDL. This guide covers particle size, ApoB, Lp(a), and what your numbers actually tell you.
Complete Guide to Blood Panel Tests: What to Ask Your Doctor
A walkthrough of every standard blood panel — CBC, CMP, lipid panel, thyroid panel — with the exact questions to ask your provider.
HIV Testing: Antibody, Antigen/Antibody, and RNA Detection Windows
Fourth-generation tests, RNA PCR, self-tests — a complete breakdown of HIV test types, accuracy windows, and what "negative" means.
Chlamydia and Gonorrhea Testing: Urine vs. Swab vs. Blood
NAAT, PCR, culture — which test is right, what sample is needed, and why home test kits are now a legitimate option.
STI Testing Window Periods: When to Get Tested After Exposure
Every STI has a window period. This guide covers HIV, chlamydia, gonorrhea, syphilis, herpes, and hepatitis detection timelines.
MTHFR, COMT, and Methylation: What Your Genetics Actually Mean
MTHFR C677T, COMT V158M, VDR Bsm — these variants show up on 23andMe constantly. What the science actually says versus the hype.
How to Read Your Raw Genetic Data File: A Practical Guide
You have a raw file with millions of lines. Here is how to open it, what the columns mean, and how to look up specific SNPs.
What Your Gut Microbiome Test Results Actually Tell You
Alpha diversity, Firmicutes/Bacteroidetes ratio, keystone species — decoding what microbiome companies report and separating signal from noise.
Why Your Cholesterol Test Is Missing the Most Important Number
Your standard lipid panel tells you your LDL cholesterol. It does not tell you how many LDL particles are actually floating through your bloodstream. That number — apolipoprotein B, or ApoB — is what the 2026 ACC/AHA guidelines now specifically recommend for millions of Americans whose LDL looks fine but whose cardiovascular risk is not.
Vitamin D Testing: What 25(OH)D Actually Tells You
If your doctor ordered a "vitamin D test," there is a roughly 50% chance they checked the wrong metabolite — or ordered a test you did not need in the first place. Here is what the numbers mean — without the hype.