Which is cheaper, DSIP or P21?

On average, DSIP is cheaper at $8.03/mg. DSIP averages $8.03/mg across 56 vendors, while P21 averages $15.22/mg across 9 vendors. Prices are updated daily.

Can you use DSIP and P21 together?

DSIP and P21 are sometimes used together. Consult a healthcare provider before combining any peptides.

DSIP vs P21

Q: What's the difference between DSIP and P21?

DSIP and P21 are both cognitive / neuro peptides with different mechanisms. Delta Sleep-Inducing Peptide, a neuropeptide studied for its role in sleep regulation, stress response, and circadian rhythm modulation.

Which should you choose? Here's what you need to know.

The short answer

DSIP and P21 are both cognitive / neuro peptides, but they work differently. Delta Sleep-Inducing Peptide, a neuropeptide studied for its role in sleep regulation, stress response, and circadian rhythm modulation. Compare vendor pricing and availability below.

DSIP

Cognitive / Neuro

Delta Sleep-Inducing Peptide, a neuropeptide studied for its role in sleep regulation, stress response, and circadian rhythm modulation.

P21

Cognitive / Neuro

Price & availability

Once you've decided which peptide fits your needs, here's how they compare on price and vendor options.

DSIP

P21

$23.00

Starting from

$61.98

$8.03

Avg. price per mg

$15.22

Vendors selling it

50 options

In stock now

6 options

9.1/10

Top trust score

9.0/10

Purity tests on file

Ready to buy?

Our top-rated vendor for each, based on trust scores, purity testing, and price.

Some outbound links may earn us a commission. Vendors cannot pay to improve rankings.

Best DSIP Vendor

Aavant Research

8.7/10

$40.00(10mg)

Best P21 Vendor

Simple Peptide

7.0/10

$198.00(10mg)

See all DSIP vendors See all P21 vendors

Where does this data come from?

We check vendor prices every day and pull in real purity test results from independent labs — not vendor claims. No vendor can pay to rank higher. See our full methodology.