P21 dosage chart
This summary table compares available dose amounts and schedules by administration route.
| Route | Dose | Frequency & duration |
|---|---|---|
| Intranasal | 200–400 mcg / day | Daily · 20–30 days |
| Injectable | ~500 mcg | Daily · 20–30 days |
P21 dosage by administration route
P21 intranasal dosage
Reported-use amounts for P21 are 200–400 mcg / day, daily, for 20–30 days.[8]
P21 is a CNTF-derived peptide associated with neuronal survival and plasticity signaling. Its identity is distinct from the cell-cycle protein also called p21.[1][2][3][8]
P21 injectable dosage
Reported-use amounts for P21 are ~500 mcg per administration, daily, for 20–30 days.[8]
P21 is a CNTF-derived peptide associated with neuronal survival and plasticity signaling. Its identity is distinct from the cell-cycle protein also called p21.[1][2][3][8]
Frequency and timing
Morning is the listed timing for both the nasal and injection patterns.[4][1][2][8]
Cycle length and breaks
Intranasal: 20–30 days. Injectable: 20–30 days. A standard break interval between courses is not established.[8]
P21 dosage calculator
Convert your chosen P21 amount into volume and U-100 syringe units. Adjust the inputs to match your vial and preparation.
P21 safety and side effects
Side effects and long-term safety
Intranasal and neuroactive effects are the most plausible practical tolerability points. Human dose-ranging, long-term neurologic safety, reproductive safety, and product consistency remain unclear. P21 safety is mainly intranasal and neuroactive, with limited human data and product-identity uncertainty.[1][2][3][4]
Common P21 dosage questions
Is the listed P21 amount a daily total?
Amounts marked /day are the total for the day. They are not an amount to repeat at each administration; the amount per administration depends on how that total is divided.[8]
What dosage is listed for P21?
Reported-use amounts for P21 are 200–400 mcg / day, daily, for 20–30 days.[8]
Does P21 have a standard cycle or break interval?
Intranasal: 20–30 days. Injectable: 20–30 days. A standard break interval between courses is not established.[8]
