Compare
P21 vs Retatrutide
Side-by-side observational reports from PeptIQ users. This compares self-reported patterns — not clinical head-to-head trials.
Observational reporting only — not medical advice. Does not recommend doses, protocols, or treatments.
P21
6 community reports
Positive 100% · Neutral 0% · Negative 0%
Most reported benefits
Cognition
6
Mood
6
Sleep
3
Dose distribution
Median: 200–400 mcg · Most common: 200–400 mcg
0–25
0
25–50
0
50–100
0
100–200
2
200–400
4
400–600
0
600–1000
0
1000–2000
0
2000+
0
Commonly stacked with
Retatrutide
125 community reports
Positive 99% · Neutral 1% · Negative 0%
Most reported benefits
Appetite
222
Most reported side effects
Nausea
3
Dose distribution
Median: 2000+ mcg · Most common: 2000+ mcg
0–25
5
25–50
0
50–100
0
100–200
3
200–400
6
400–600
10
600–1000
5
1000–2000
80
2000+
113
Commonly stacked with
How repeat users are trending
Among repeat reporters, 100% said they felt similar to their last entry, 0% more positive, and 0% more negative.
Overall, repeat reporters leaned similar or mixed compared to their previous entry.
Median gap between entries: 51 days · Based on 45 repeat reporters