Comparing the outcomes
The measurement that convinces me changes with the job. Weight, circulation, muscle glucose handling and survival deserve their own columns.
Results beside their intended jobs
The word activity can hide an enormous difference in what actually happened. A receptor can respond in a dish, blood flow can recover in a rat, and a person can survive an illness. Each observation matters at its own scale.
Ranking these compounds obscures the jobs that interest me. NAD+ is chemically a coenzyme; the other subjects are peptides. The useful comparison begins with the outcome, then checks the setting in which it was measured.
| Subject | Work being examined | Finding in the record | Remaining question |
|---|---|---|---|
| NAD+ precursors | Cellular supply and metabolic function | NMN improved muscle insulin sensitivity in postmenopausal women with prediabetes; HbA1c and body composition stayed unchanged | Does the measured change produce lasting health benefit? |
| Retatrutide | Appetite and metabolic signalling | Phase 2 human trials found weight loss; liver-fat and diabetes studies found changes in their own populations | How durable are the benefits, and what are the longer-term risks? |
| BPC-157 | Blood supply and repair | Vessel growth and blood-flow recovery improved in animal and cell models | Do injured people recover better? |
| Thymosin alpha-1 | Immune response during severe illness | The phase 3 sepsis trial found no significant survival benefit | Which other clinical settings, if any, have dependable benefits? |
Where I put the emphasis
For NAD+ precursors, the review of human ageing research makes tissue-specific evidence a pressing gap. A higher blood level leaves much of the body unexplained. For BPC-157, the human evidence review makes a different shortage plain: rigorous large-scale human trials are lacking.
Retatrutide already has measured human weight outcomes in this record. The heart-rate and gastrointestinal findings in the obesity trial belong in the same appraisal as the weight loss. Thymosin alpha-1 presents the reverse temptation: discarding the disappointing survival result because a cellular explanation remains attractive.
I give a clear disappointment more weight than a mechanism pressed into the wrong job. That still leaves plenty to investigate. The linked subject pages pursue NAD+, retatrutide, BPC-157 and thymosin alpha-1 as separate stories.