The Signal
Notes on hormones, longevity, and what your labs are really saying.
Written and reviewed by Erica Finnan, MSN, APRN-C — hormone, thyroid, and longevity specialist.
Fasting insulin: the early warning marker your annual physical skips
Insulin can be elevated for a decade before glucose ever moves. Why this single number is one of the most predictive things in your bloodwork.
Beyond TSH: the thyroid panel most providers don't run
Free T3, Free T4, reverse T3, and antibodies tell a story TSH alone can't. A specialist's guide to a complete thyroid picture.
ApoB vs. LDL: the cardiovascular marker worth asking for
ApoB counts the actual particles that drive plaque. Why longevity specialists prefer it over standard cholesterol panels.
Perimenopause: the hormone shifts that start in your 30s
Estrogen, progesterone, and testosterone don't fall off a cliff at 50 — they fluctuate for years. What to test and when.
Healthspan vs. lifespan: living well, longer
The last 15 years of an American life are often spent in decline. Here's what the science says about compressing that window.
Men, testosterone, and the slow decline no one warns you about
Total T, free T, SHBG, and estradiol — the markers that actually explain energy, mood, and body composition shifts.
Stay in the loop
New research, decoded into plain English.
Get a monthly note from Erica with what's worth paying attention to in hormone health and longevity science.