Which blood tests to get, and when to start
Casey Means, Sara Gottfried, Kyle Gillett and Peter Attia each lay out biomarkers worth tracking by age and sex, from glucose and insulin to hormones and lipids. Starting a baseline early lets you catch drift years before disease.
Get a basic baseline as early as you can, before anything is wrong, and repeat it about twice a year. Five physicians and scientists overlap on which blood tests matter, and they all agree on timing, because insulin, hormones and lipids can drift for years before a diagnosis appears.
Casey Means starts with the seven markers of metabolic syndrome, most of which come with an ordinary physical: fasting glucose, triglycerides, HDL cholesterol, hemoglobin A1c, the ratio of total cholesterol to HDL, waist size and blood pressure. She adds fasting insulin, ApoB and hs-CRP where a doctor will order them. Her distinctive advice is to read results together. Glucose and triglycerides that are both high but technically normal tell her one story, insulin resistance.
Sara Gottfried, an obstetrician-gynecologist, wants women to have a hormone baseline of estrogen, progesterone and testosterone in their 20s and 30s. Because hormones shift across the month, she times the draw to about day 21 or 22 of a 28-day cycle, and earlier as cycles shorten. She stresses insulin, which she says can change years before glucose does. Her advice: "Do it as soon as possible." She also recommends a coronary artery calcium scan by 45, earlier with a family history of premature heart disease.
Kyle Gillett says bloodwork can begin in the teen years when parents and child agree, especially with concerns about puberty or growth. For men he wants testosterone measured with SHBG or as free testosterone, since total alone can mislead. He suggests a follow-up about every six months.
Peter Attia puts apoB first for heart disease risk and wants lipoprotein(a) measured once early in life, since it is genetic. Not knowing it at 20, he says, is "leaving money on the table." He adds that bloodwork is much weaker for cancer risk, and he relies on functional tests such as DEXA scans and VO2 max for healthspan.
David Sinclair adds HbA1c, high-sensitivity CRP and iron, and argues for judging results against your own history over years.
They differ on the headline lipid marker, on how often to test, and on sample type. Gottfried prefers saliva and dried urine for some hormones while granting that blood is the standard and the cheapest. They also push against treating the lab's printed range as the goal, though in different directions. Twice a year is the common floor, with more testing while you try a change.
The article sets limits. Testing does not replace a doctor. Results must be read by a qualified physician, and with any abnormal result, or before starting hormones, supplements or medication, you should work with a physician who knows your history. It also does not mean chasing every number, and a basic panel gives most of the value.
What to do with it: get a baseline now, whatever your age. Test lipoprotein(a) once. Men should ask for free testosterone or SHBG. Women should time hormone draws to the cycle. Repeat every six months. Read results together and against your earlier numbers. Tell your doctor honestly what has changed.