Longevity, on the record
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The 14 questions take about 3 minutes and need no labs. You see how many targets you hit, the one holding you back most, and the minute each target was said on tape.
Your score is free, with no account, in about 3 minutes. The checked PDF report is optional.
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Every target and verdict traces to a source: 3,700+ hours of recorded interviews with 380+ researchers and doctors, and 87,700+ research studies.
11 targets, biggest effect firstNo labs
1 · VO2 max
5×
the gap in death risk between the least fit quarter and the fittest 2.5%
Said on tape · receipt ▶Target: elite for someone 20 years younger
Ranked by tier, then by the size of the effect on record. Dead hang and push-ups show the targets for men; the assessment sets yours by sex.
No brand pays us. There are no affiliate links and there is no storefront. Our readers and subscribers fund Precis, so a verdict can go against a supplement here and nothing happens to us.
“It's hard to know which heads to listen to.” That comment has 2,300 likes. Some version of it turns up 2,189 times in the 298,879 comments on these six channels, and it rose by about half across 2025.
Without Precis. One magnesium answer sits in 17 videos, and nothing tells you which one is right.
With Precis. Every mention is counted once into one verdict, and each line links to its minute.
Glycinate or malate for the daily dose. Bisglycinate or threonate for sleep. Each form gets its own recommendation. Which do you take?
Magnesium glycinate and malate are better absorbed than other forms of magnesium.
4 sources: 1 positive, 2 partly, 1 negative 4 counted mentions from 4 sources
Magnesium glycinate is a better form for sleep than magnesium threonate.
No counted mention yet. No counted mention yet
A real viewer wrote that. One magnesium answer sits in 17 videos. Creatine took 50 videos and 85 hours. Positions also change, and nobody has time to catch the update.
ChatGPT gives you an answer. It rarely gives you the name and the minute behind it. An answer with no source is a guess in a confident voice.
Step 1
They cover your age, sleep, training and a few fitness tests you can do at home, and they take about 3 minutes with no labs and no account.
Step 2
We score you on 11 targets that researchers set on the record, biggest effect first, and name the one holding you back most. Each target links to the minute it was said.
Step 3
Type in your blood panel free with an account and 25 more targets count, or get the checked PDF report with a 5-week program.
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Protein is target 7 of 11. The number on record is 1.6 g per kg a day, and not everyone on tape agrees with it.
1.6 g/kg
A single number for everybody, about 1.6 g per kg of body weight.
Dr. Peter Attia · the target the assessment uses · on tape ▶
1.2–1.4 g/kg
Enough for most people; the 1 g per pound camp has no data behind it and is dangerous.
Dr. Eric Topol · on tape ▶
0.8 g/kg
The official 0.8 g per kg is a safe level, and most people already eat about 1.4.
Prof. Tim Spector · on tape ▶
The assessment scores you against 1.6 and shows the other two views beside it. You decide with your doctor.
The method has three steps and none of them is a judgment call.
We read every video on the topic and log each mention of a claim. Own research or an opinion counts for the person who said it. A cited study counts for the study, once. A host's remark inside an interview is not counted.
Every counted mention of a claim feeds one verdict: Strong consensus, Leaning, Mixed, Conflicting or Not enough evidence. Fewer than 3 counted mentions, or a single source, reads Not enough evidence.
Every counted mention carries the video and the minute, or the study. Go listen.
The three steps, run on creatine
50
videos read
85
hours of tape
11
counted mentions from 11 sources
the verdict that count produces
The verdict moves only when a new mention is counted. Nothing here is our opinion.
Most people come here to add something. The more useful half of this page is the bottom row.
Where the evidence agrees
35 counted mentions from 35 sources
20 counted mentions from 20 sources
14 counted mentions from 14 sources
Where the sources split
22 counted mentions from 22 sources
7 counted mentions from 7 sources
Conflicting means the counted sources take both sides.
6 of 44 topics do not have enough counted evidence for a verdict yet.
39 more topics, from Vitamin D to fasting and HRT.
Browse All ReportsA report tells you what the sources said. Chat answers the follow-up: what did any of them say about this next to my labs, my meds, my age. Every answer still carries the expert, the video and the minute.
You don't have to trust us. Check the tape.
My magnesium is normal but my vitamin D is low. Do I still need magnesium?
A normal result doesn't settle it. Around 99% of your magnesium sits inside cells, so a serum test reads a sliver of it. Your body also pulls from bone to hold that number steady. A real shortfall can hide behind a clean report. Magnesium is also what turns vitamin D into the form your body uses.
When do I take them?
Magnesium in the evening. Huberman suggests 300 to 400mg, 30 to 60 minutes before bed. Take vitamin D with a meal that has fat in it, since it is fat-soluble and you absorb little without fat. Morning or midday is the better slot.
Chat is part of Pro. The full reports need only a free account.
Free shows the verdict, every counted mention and every timecode. A free account adds the dose, form and timing claims. Pro adds Precis Chat and unlimited Ask, for $79 a year or $9 a month.
It costs $79 because we already did the reading. The same 3,700+ hours of recorded interviews with 380+ researchers and doctors, plus 87,700+ research studies answer your question and everyone else's. Nobody bills you for a researcher's afternoon.
We do the reading so you don't have to
billed $79 a year, a 26% saving
Longevity isn't a 30-day trial. Biomarker shifts take months to show up on a blood panel. Annual covers a full testing cycle, spring through winter.
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The average health optimizer spends $214 a month on supplements. If Precis helps you drop the ones the evidence doesn't back, it pays for itself in the first month. Spend figures: Sanctuary Wellness Institute, 2025.
Questions
We didn't build Precis for people who read the trials themselves. We built it for the reader who wrote "just tell me the 6 things." That's why every verdict comes with a count you can check, and every line links to the minute it was said or the study it came from.
No. No brand pays us. There are no affiliate links and there is no storefront. Only readers pay us, through Pro or a one-off $49 health assessment that scores you against the optimal targets researchers set on the record. A free account opens the dose, form and timing for every topic, and your saved stack. Pro adds unlimited chat and Ask. You are the customer, not the product. That is why we have no reason to prefer one magnesium form over another.
Plenty of people do, and it answers fast. The difference is what comes back with the answer. Every claim here names the person who said it, the video and the minute. You can open the source and hear it yourself. Where someone cites a study, we surface that too. We draw from one fixed set of videos we have read. If nobody said it on tape, we don't print it. That rule is the whole product. We never ask you to take our word for anything. Reports update monthly, or sooner when a source changes position.
Each claim gets one verdict, computed from every counted mention of it in 3,700+ hours of recorded interviews with 380+ researchers and doctors, plus 87,700+ research studies. Own research or an opinion counts for the person who said it. A study they cite counts for the study, once. A host's remark inside an interview is not counted. The verdict reads Strong consensus, Leaning, Mixed, Conflicting or Not enough evidence, with the direction for or against. Each counted mention links to its video and timestamp, or to its study.
Researcher interviews on the longevity channels we follow: 3,700+ hours of recorded interviews with 380+ researchers and doctors, plus 87,700+ research studies. Someone counts as a researcher or doctor only when an episode title puts Dr., Professor, PhD or MD next to their name. Every recommendation traces back to a specific video and timestamp.
Across 3,700+ hours of recorded interviews with 380+ researchers and doctors, plus 87,700+ research studies, this is where the evidence lands on the main claim for each supplement. Strong consensus for: Creatine and Magnesium. Leaning for: Probiotics & Gut Health, GLP-1 Agonists, Omega-3, Glutathione, Caffeine, Melatonin, Vitamin D, Vitamin B12, NAC, Electrolytes, Ashwagandha, Folate, Garlic, Glycine, Zinc, CoQ10, Vitamin C, Iron, Curcumin, and Selenium. Mixed: NMN & NAD+. Conflicting: Collagen. Leaning against: Metformin. 5 of the 30 supplement reports do not have enough counted evidence for a verdict yet. We track 50 supplements and publish 44 full reports.
No. We report what researchers say in public, on tape. Precis is an information tool, not a medical provider. Every claim links back to its source video and timestamp so you can check it yourself. Talk to your doctor before you change your health routine.
Arun Agrahri builds Precis. One person, no team, no medical license. Every dose on the site had to match a line in a real transcript before it shipped. How it works →
Also free, and none of it needs an account.
One short email a week: the claims and evidence that moved, where the record disagrees, and whether any of it is worth doing. Every claim links to the minute it was said. In 17 issues so far, we marked 3 of 90 new claims worth acting on.
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