Testosterone 101

Everything you need to know about testosterone, backed by the latest research. We turn complex topics like diagnosis, dosing, delivery methods, and lab results into simple, practical insights. Understand TRT benefits and risks, maintain estradiol balance, and spot drug interactions - all grounded in evidence, not hype.

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The essentials for testosterone 101 — then explore the latest posts below.

Function Health testosterone results: What “out of range” really means and what to do next

Function Health testosterone results: What “out of range” really means and what to do next

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Feb 09, 2026 · 13 min read

An “out of range” testosterone result means your value fell outside that lab’s reference interval, not that you have hypogonadism. The next step is to repeat a morning total testosterone and add confirmatory labs (free testosterone with SHBG, plus LH/FSH) interpreted alongside symptoms before deciding on treatment. “When a lab report says ‘normal’, it mostly ...

Testosterone and the Dietary Guidelines for Americans: What men should actually do

Testosterone and the Dietary Guidelines for Americans: What men should actually do

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Jan 21, 2026 · 12 min read

The Dietary Guidelines for Americans (DGA) do not provide testosterone targets. Men can use the DGA to support a healthy body weight and cardiometabolic health, which can indirectly support testosterone, and should seek medical evaluation for persistent symptoms or repeatedly low morning labs. Here’s what diet can improve, what it can’t, and how to act ...

Athlete biomarker testing for longevity: The lab numbers that keep men performing longer

Athlete biomarker testing for longevity: The lab numbers that keep men performing longer

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Jan 19, 2026 · 12 min read

For longevity-focused men who train, repeating key labs, especially HbA1c (a three month average of blood sugar) and ApoB (the number of atherogenic particles that can enter artery walls), can reveal early metabolic drift and cardiovascular risk before performance drops or disease shows up. Pair those with iron, inflammation, and hormone and recovery markers to ...

Does creatine increase testosterone? The science on muscle fuel and male hormones

Does creatine increase testosterone? The science on muscle fuel and male hormones

Dr. Alexander Grant, MD, PhD avatar
Dr. Alexander Grant, MD, PhD: Urologist & Men's Health Advocate
Jan 11, 2026 · 11 min read

Creatine monohydrate does not significantly increase total or free testosterone in healthy men in controlled studies, because it works by boosting cellular energy (ATP recycling) rather than directly stimulating the endocrine system. It may still help you train harder and see temporary workout-related hormone spikes. A single 2009 rugby study reporting higher DHT (a potent ...

9 foods that fight hot flashes in men and what to avoid

9 foods that fight hot flashes in men and what to avoid

Dr. Alexander Grant, MD, PhD avatar
Dr. Alexander Grant, MD, PhD: Urologist & Men's Health Advocate
Jan 07, 2026 · 12 min read

Certain foods and diet patterns can help reduce hot flash frequency and intensity in men, especially when episodes are linked to hormone shifts, blood sugar swings, or inflammation. The best approach is not one “miracle food,” but a repeatable way of eating that keeps your internal thermostat more stable. “In men, hot flashes are often ...

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