The Learn Hub
Hormone health,
plainly explained.
Evidence-based guides on testosterone, GLP-1s, peptides, and Hypospray delivery, written by clinicians, reviewed by clinicians, cited to the source.
Evidence-based guides on testosterone, GLP-1s, peptides, and Hypospray delivery, written by clinicians, reviewed by clinicians, cited to the source.
Evidence-based guides on testosterone optimization, TRT clinical science, delivery methods, low-T symptoms, and the comparisons that matter.
What testosterone, estrogen, and progesterone actually do in the female body — the research gaps nobody talks about, and dosing built around female physiology.
How a transdermal spray rewrites the pharmacokinetics of hormone delivery. Cross-cutting science underlying Keen products for men and women.
130 articles across 21 series, citing 82 peer-reviewed sources.
Every clinical claim is checked against the primary literature. Every figure we could not attribute was dropped rather than softened.
Practical questions — what a membership covers, the lab panel, using the spray — are answered in the Learn Hub FAQ.
The Endocrine Society guideline is explicit: a single low reading is not a diagnosis. It has to be a fasting morning draw, and it has to be repeated. Most men who get tested badly get tested once, in the afternoon, without fasting.
4 min readPersistent tiredness in men over 35 is often written off as stress or age. Here is the physiology linking low testosterone to fatigue, what the pattern looks like clinically, and which other causes need ruling out first.
6 min readTotal testosterone is one number on a page, and it is the least informative one for a large group of men. Understanding a result means knowing what fraction of it your tissue can actually use — and most basic panels don't measure that.
4 min readThe 5,246-man RCT behind the FDA's 2025 cardiovascular safety update on testosterone therapy. What it measured, what it found, and what it changes for men on TRT today.
4 min readWomen produce testosterone and levels fall with age, but the evidence supports exactly one indication for treating it. Here is what the randomized trials found, what they did not, and why no testosterone product is approved for women.
5 min readThe transdermal spray platform Keen uses has peer-reviewed pharmacokinetic and clinical data behind it, across two different drug classes. Here is what each study measured, what it found, and what it does not establish.
6 min read