Evidence-graded books for the second half of life
Five independent books on weight, aging, hair, skin and menopause. Every claim carries a grade for its evidence, the prices are real and dated, and nothing is sponsored.
Each book takes one question, grades everything sold for it, and ends with a plan you can start this week.
Costs a fraction of the pen.
Evidence-based weight loss, without the subscription
Protein, fiber, food order, sleep and 20-minute workouts, graded honestly and costed in real grocery prices, with an off-ramp plan for coming off the drug.
80+ studies. 40+ interventions graded. Nothing to buy.
The evidence-graded guide to what actually slows your pace of aging, and what does not
Over 80 peer-reviewed studies ranked into one priority list for adults over 40, with failed and sponsored studies flagged and a 30-day plan.
You’re not imagining it. And you’re not out of options.
From worry and guesswork to clear answers, proven options and a 90-day plan
The independent guide for women: every option rated, 110 sources tagged with who paid for them, and a 90-day plan.
You’re not aging badly. You’re being sold badly.
What slows skin aging, what is marketing, and what to pay for at every age
Every ingredient, device and clinic treatment graded for evidence and value, with age-by-age plans from 30 to 70 and US and Seoul prices.
For women at and after menopause.
Peptides and hormones debunked: what works, what is marketing, and what to pay
HRT, vaginal estrogen, testosterone, GLP-1s and 20 clinic peptides, graded against the human trials and costed in US dollars and UK pounds.
The PrimeSpan library
Weight, aging, hair, skin and hormones are connected, and so are the books. Get every guide in one purchase.
Each book comes with a free two-page guide. No email needed: read one tonight, then decide.
What you can check for yourself before you buy.
No sponsored content, no paid placements and no affiliate links. Brands appear only when a study or regulator named them.
When the only proof comes from the company selling the product, the book tells you.
Where a book prices an option, it gives a real price and the date it was checked: US dollars throughout, plus UK pounds in the weight, hair and menopause books.
No miracle cures and no promises. You get what the evidence supports, and the questions to take to your clinician.
PrimeSpan is an independent publisher of research guides. Each book is a synthesis of published research, prepared with AI assistance from the studies, regulator documents and guidelines it lists at the back. Every key claim carries an evidence grade, so you can see how strong it is and look it up.
No PrimeSpan book has been written or reviewed by a doctor or other clinician. They are not medical advice. Use them to understand your options and to prepare for an appointment, never instead of one.
The 5 Free Hunger Levers
Twelve things the aging research says
Free excerpt: Is this normal?
The Skip List
20 Peptides, Graded