MOTS-c vs SS-31
At 10mg, the only strength both sell by the single box, MOTS-c is the cheaper per mg: $0.783 per mg against $0.889 (MS10, 2S10). MOTS-c is offered in 4 strengths (10mg to 40mg), SS-31 in 2 (10mg to 50mg). Neither is on the shelf today.
Prices revised · USD per box of ten · freight included to US addresses from $1,000 of goods · COA per batch · research use only · New to us? What can be checked before you pay
What differs between MOTS-c and SS-31
Sixteen residues against four, and the mass gap says it: MOTS-c is C101H152N28O22S2 at 2,174.6, CAS 1627580-64-6; SS-31 is C32H49N9O5 at 639.8, CAS 736992-21-5, less than a third of the mass. Only MOTS-c has a methionine or a tryptophan to oxidise: its two sulfur atoms are both methionines, and it has a tryptophan at 3; SS-31 has no sulfur and no tryptophan. SS-31 is built from residues that are not standard, a D-arginine and a dimethylated tyrosine among them. On this list MOTS-c is offered in four strengths from 10 to 40 mg and SS-31 in two, 10 and 50 mg, so the per-milligram comparison below is across quite different vial sizes.
| Detail | MOTS-c | SS-31 |
|---|---|---|
| Best price per mg | $0.669 per mg (MS40) | $0.771 per mg (2S50) |
| Price per box sold singly | $78.32 to $267.43 | $88.90 to $385.62 |
| In 50-box lots, per box | $110.04 | None |
| Strengths offered | 4: 10mg, 15mg, 20mg, 40mg | 2: 10mg, 50mg |
| Highest price per mg | $0.783 per mg (MS10) | $0.889 per mg (2S10) |
| On the shelf today | 0 of 4 strengths | 0 of 2 strengths |
| Range | Longevity & Nootropic | Longevity & Nootropic |
| Also called | No other name | elamipretide, MTP-131 and RX-31 |
| Form | Lyophilised powder | Lyophilised powder |
| Molecular weight | 2,174.6 g/mol | 639.8 g/mol |
| Formula | C101 |
C32 |
| CAS number | 1627580-64-6 | 736992-21-5 |
| Release limit | Purity ≥ 98.0 % by RP-HPLC | Purity ≥ 98.0 % by RP-HPLC |
Each line’s own page: MOTS-c and SS-31. Reading either certificate: how to read a peptide COA. Checking a batch: verify a batch number. Every line priced: the price list. Checking another supplier’s quote: the price per mg calculator.
Strength for strength
Every strength both are offered in, per mg, the lower figure in bold; stock as this page was opened.
| Strength | MOTS-c | SS-31 |
|---|---|---|
| 10mg | $0.783 per mg (lower) (MS10, made to order) | $0.889 per mg (2S10, made to order) |
Every strength of both
Compared elsewhere
Questions
What is the difference between MOTS-c and SS-31?
Sixteen residues against four, and the mass gap says it: MOTS-c is C101H152N28O22S2 at 2,174.6, CAS 1627580-64-6; SS-31 is C32H49N9O5 at 639.8, CAS 736992-21-5, less than a third of the mass. Only MOTS-c has a methionine or a tryptophan to oxidise: its two sulfur atoms are both methionines, and it has a tryptophan at 3; SS-31 has no sulfur and no tryptophan.
Which residues turn up in both MOTS-c and SS-31?
Lysine and phenylalanine, one of each in both chains. SS-31’s arginine is the D form, where the three in MOTS-c, in places 2, 13 and 16, are L, and its 2,6-dimethyltyrosine is a non-coded relative of the two tyrosines MOTS-c carries at 8 and 11. For all the difference in length, the two share a charge of roughly +3 at pH 7. SS-31 closes on its phenylalanine as an amide, while MOTS-c runs on to arginine 16.
Which is cheaper per mg, MOTS-c or SS-31?
At 10mg, the only strength both sell by the single box, MOTS-c is the cheaper per mg: $0.783 per mg against $0.889 (MS10, 2S10).
What are the molecular weights of MOTS-c and SS-31?
MOTS-c’s calculated average mass is 2,174.6 g/mol and SS-31’s 639.8 g/mol, 1,534.8 apart; in electrospray the ions come at m/z 1088.3 and 725.9 (2+ and 3+) for MOTS-c against 640.8 (1+) for SS-31. On each certificate the measured mass is matched to the line’s calculated average mass, within about one unit, as how to read a peptide COA sets out.
Are MOTS-c and SS-31 made to the same specification?
Yes: both are supplied to purity not less than 98.0 percent by RP-HPLC and net content within 5 percent of label, and each certificate reports those with a measured mass, matched to the calculated figure on each sheet. The retest date is on the batch record. What differs is each molecule’s own chemistry, described on its compound page.
Structural facts from each compound’s sheet and profile; prices and stock from the list at the moment this page was opened. How to compare strengths on price.