Compare the question before comparing the result.

These selected examples help you read studies. They do not select a treatment or rank compounds. Methods and source checks.

Cardiovascular outcomes: who was studied?

SELECT and LEADER each compared an active treatment with placebo. Their diabetes criteria and baseline risks differ. They are not a head-to-head trial.

Who took part, what was measured, and what the study found
Study and people	Question and follow-up	Result and limits
SELECT Age 45+, established cardiovascular disease, BMI ≥27, no diabetes 17,604 participants (actual) Randomized placebo-controlled trial; human	Semaglutide versus Placebo Mean follow-up 39.8 months Primary: First cardiovascular death, nonfatal heart attack or nonfatal stroke Phase: Not listed in this summary Registry status: Not assessed Registry results: Not assessed Publication: published; peer reviewed	569/8803 (6.5%) versus 701/8801 (8.0%) had a primary event. 1.5 percentage points fewer events, using rounded published proportions. Hazard ratio 0.80; 95% CI 0.72–0.90. A hazard ratio is not a risk ratio. Cannot tell us: A secondary-prevention population; not a trial in healthy adults or a head-to-head comparison. Safety, uncertainty, and source details Discontinuation due to adverse events: 16.6% versus 8.2%. Limited to the studied population, formulation and follow-up. Funding/conflicts: Funded by Novo Nordisk; individual disclosures not fully extracted. Source checked: 2026-09-18. Independent clinical review: not completed.
LEADER Type 2 diabetes and high cardiovascular risk 9,340 participants (actual) Randomized placebo-controlled trial; human	Liraglutide versus Placebo Median follow-up 3.8 years Primary: First cardiovascular death, nonfatal heart attack or nonfatal stroke Phase: Not listed in this summary Registry status: Not assessed Registry results: Not assessed Publication: published; peer reviewed	608/4668 (13.0%) versus 694/4672 (14.9%) had a primary event. 1.9 percentage points fewer events, using rounded published proportions. Hazard ratio 0.87; 95% CI 0.78–0.97. Cannot tell us: Population differs from SELECT; these two placebo comparisons cannot rank liraglutide against semaglutide. Safety, uncertainty, and source details Gastrointestinal events most commonly led to discontinuation. Limited to the studied population, formulation and follow-up. Funding/conflicts: Novo Nordisk and NIH; individual disclosures not fully extracted. Source checked: 2026-09-18. Independent clinical review: not completed.

Why this comparison cannot rank treatments

We align reported populations, primary outcomes, duration and uncertainty. We do not pool studies or adjust for differences in baseline risk. An indirect comparison is a research-reading exercise, not a statistical estimate of comparative effectiveness. Registry results, published papers and regulatory decisions are checked separately. When a detail has not been confirmed, we say so.

NAD+, NR and NMN: which question was tested?

These are different entities, formulations, populations and follow-up periods. Metabolite handling, cognition and physical performance are different questions. No winner can be inferred.

Who took part, what was measured, and what the study found
Study and people	Question and follow-up	Result and limits
NAD+ metabolome pilot Human infusion cohort; full participant details not extracted Participant count not confirmed in this summary Pilot pharmacokinetic study; human	NAD+ versus Not extracted Six-hour exposure with short-term sampling Primary: Plasma and urine NAD-related metabolites Phase: Not listed in this summary Registry status: Not assessed Registry results: Not assessed Publication: published; peer reviewed	The report describes metabolite handling during and after exposure. Cannot tell us: Does not measure longevity, addiction recovery, cognition or durable functional benefit. Sample size and full risk assessment are not extracted. Safety, uncertainty, and source details See primary paper; absence of a signal in this study does not establish general safety. Limited to the studied population, formulation and follow-up. Funding/conflicts: Not confirmed in this summary; check the full paper. Source checked: 2026-09-18. Independent clinical review: not completed.
NR mild cognitive impairment pilot Older adults with mild cognitive impairment 20 participants (actual) Randomized placebo-controlled trial; human	Nicotinamide riboside versus Placebo 10 weeks Primary: Change in Montreal Cognitive Assessment score DNA methylation; secondary blood NAD+ and other functional measures. Phase: Not listed in this summary Registry status: Not assessed Registry results: Not assessed Publication: published; peer reviewed	Blood NAD+ increased; cognition did not change. Cannot tell us: Too small and short to establish prevention of dementia or rare harms. Cerebral blood-flow findings did not survive correction for multiple comparisons. Safety, uncertainty, and source details No between-group difference in reported adverse events in this small pilot. Limited to the studied population, formulation and follow-up. Funding/conflicts: Not confirmed in this summary; check the full paper. Source checked: 2026-09-18. Independent clinical review: not completed.
MIB-626 NMN study Adults aged ≥45 with overweight or obesity 30 participants (actual) Randomized placebo-controlled trial; human	Nicotinamide mononucleotide versus Placebo 28 days Primary: Safety, NAD metabolism and physiological measures; endpoint hierarchy not extracted Phase: Not listed in this summary Registry status: Not assessed Registry results: Not assessed Publication: published; peer reviewed	Circulating NAD increased; strength, fatigability, aerobic capacity and stair-climbing changes did not differ significantly. Cannot tell us: Multiple short-term outcomes; no inference about lifespan. This formulation cannot represent every NMN product. Safety, uncertainty, and source details Reported adverse events were similar between groups over 28 days. Limited to the studied population, formulation and follow-up. Funding/conflicts: Not confirmed in this summary; check the full paper. Source checked: 2026-09-18. Independent clinical review: not completed.

Why this comparison cannot rank treatments

Weight studies: published results versus registered comparisons

SURMOUNT-1 and the retatrutide Phase 2 study were separate placebo comparisons. TRIUMPH-5 is a registered direct comparison; its record does not yet contain results at the source check.

Who took part, what was measured, and what the study found
Study and people	Question and follow-up	Result and limits
SURMOUNT-1 Adults with obesity or overweight plus a complication; diabetes excluded 2,539 participants (actual) Randomized placebo-controlled trial; human	Tirzepatide versus Placebo 72 weeks Primary: Percentage weight change and proportion reaching at least 5% reduction Phase: Phase 3 Registry status: Not assessed Registry results: Not assessed Publication: published; peer reviewed	Active groups had greater mean weight reduction than placebo. Cannot tell us: Weight change alone does not quantify cardiovascular-event or survival benefit; different active regimens are not pooled here. Safety, uncertainty, and source details Gastrointestinal events were most common; adverse events led to discontinuation in both active and placebo groups. Limited to the studied population, formulation and follow-up. Funding/conflicts: Supported by Eli Lilly; individual disclosures not fully extracted. Source checked: 2026-09-18. Independent clinical review: not completed.
Retatrutide Phase 2 Adults with obesity or overweight plus a weight-related condition 338 participants (actual) Randomized placebo-controlled trial; human	Retatrutide versus Placebo 48 weeks; primary endpoint at 24 weeks Primary: Percentage body-weight change at week 24 Weight change at week 48 was secondary, not the primary endpoint. Phase: Phase 2 Registry status: Not assessed Registry results: Not assessed Publication: published; peer reviewed	Greater weight reductions than placebo were reported. Cannot tell us: A Phase 2 result is neither approval nor a direct comparison with semaglutide or tirzepatide. Safety, uncertainty, and source details Gastrointestinal events and increases in heart rate were reported. Limited to the studied population, formulation and follow-up. Funding/conflicts: Funded by Eli Lilly; individual disclosures not fully extracted. Source checked: 2026-09-18. Independent clinical review: not completed.
TRIUMPH-5 Adults with obesity 800 participants (estimated) Randomized placebo-controlled trial; human	Retatrutide versus Tirzepatide Primary weight endpoint: 80 weeks Primary: Percentage body-weight change Phase: Phase 3 Registry status: ACTIVE_NOT_RECRUITING Registry results: Not posted Publication: not assessed; not peer reviewed	Active, not recruiting; no registry results posted at the source check. Cannot tell us: A registered head-to-head design is not a completed head-to-head result. Enrollment is estimated. Safety, uncertainty, and source details See primary paper; absence of a signal in this study does not establish general safety. Limited to the studied population, formulation and follow-up. Funding/conflicts: Sponsor: Eli Lilly and Company. Source checked: 2026-09-18. Independent clinical review: not completed.

Why this comparison cannot rank treatments

Explore individual records · Work through trial-reading examples