Source Disagreements and Name Mix-ups

Unresolved in this Library (13)

The record sets out what each source prints and does not choose between them.

• Sequence

  Order of Val and Ser at peptide positions 9 and 10

  The 1993 native-fragment abstract (PMID 8358331) gives LRIVQCRVSEGSCGF, transposing Val and Ser at canonical mature GH1 positions 184-185 relative to LRIVQCRSVEGSCGF…

• One source, two statements

  Position of the added tyrosine within one FDA briefing

  The FDA December 2024 briefing places the added Tyr at the N-terminus in its chemistry description and Figure 4, but its narrative on printed page 24 says C-terminus.

• Formula or mass

  Average mass from two calculations

  The dossier preserves a numerical discrepancy with the GSRS value of 639.79 whose atomic-weight convention was not established.

• Sequence

  Alpha subunit residue 4: threonine or valine

  The two crystal-structure depositions differ at alpha position 4: PDB entry 1HRP records threonine and PDB entry 1HCN records valine.

• Residue count

  Beta subunit length: 145 or 147 residues

  …the cDNA encodes a 145-amino-acid chain with a 20-amino-acid presequence (Fiddes and Goodman, 1980), while an earlier protein-sequencing report described 147 residues (Carlsen et al., 1973).

• Formula or mass

  Average mass: PDB entry vs GSRS

  Two published average-mass values differ and remain unreconciled: 3769.136 in the PDB entity metadata for entry 2L63, and 3760.0 as the GSRS estimated calculated weight.

• Sequence

  Residue 4: glutamine or glutamate

  The Gln4 versus glutamyl4 source disagreement leaves the complete sequence, molecular formula and average molecular mass unresolved; those fields are withheld.

• Stereochemistry

  Configuration of the residue at position 13

  The drawing of the position-13 residue in CN117024528B shows the opposite configuration to the one WHO specifies; whether that is a different stereoisomer or a drawing error is not established here.

• Formula or mass

  Molecular formula and mass: WHO INN list vs FDA GSRS

  No molecular formula or molecular mass is recorded as a field, because two public records print different values. WHO Proposed INN List 128 prints C221H342N46O68 for the free peptide…

• Registry record

  PubChem records filed under the name retatrutide

  PubChem links several compound records to substance records carrying this name, those records differ from one another in stereochemical detail and in one case in composition, and none has been matched to an independently established structure.

• Registry number

  Registry numbers given for N-acetyl Selank amidate

  Registry numbers reported for that modified variant are inconsistent across suppliers and no CAS for it is published here.

• Formula or mass

  Molecular formula and weight across registry records

  The retrieved registry representations disagree on molecular formula and molecular weight. Their reported properties are retained as conflicting observations; no settled formula or average molecular weight is assigned here.

• Sequence

  Complete sequence, formula and mass across sources

  The complete sequence, molecular formula and average molecular mass remain conflicted and are withheld.

This Library follows one source (23)

The record states which value it uses and notes the other.

• Registry record

  Human amylin's C-terminus in the Guide to Pharmacology

  The IUPHAR/BPS Guide to Pharmacology (ligand 687, release 2026.3.1) names an amidated C-terminal proline in its modification text while its own sequence ends in amidated tyrosine; this record keeps the Tyr37 amide.

• Structure description

  Glu14 and Arg17: noncovalent contact or an extra ring

  The Glu14–Arg17 interaction reported for this peptide is a noncovalent ionic contact, not a lactam bridge. Descriptions that render it as an additional covalent ring describe a different molecule.

• Formula or mass

  Oxygen count in the molecular formula: O58 or O59

  An FDA substance record displays C194H312N54O58S2 against an approximately 4409 Da mass. That oxygen count is inconsistent with both the stated mass and the covalent structure; reconstruction gives O59, matching PubChem.

• Structure description

  Where cagrilintide's lipid is attached

  A 2026 review by Bousch et al. (PMID 41898461) instead describes the N-terminal lysine as lipidated on its side chain; this record keeps the alpha-amino attachment stated above.

• Registry record

  Cosyntropin's stereochemistry in PubChem

  PubChem CID 16129617, the entry titled Cosyntropin, and CID 16129674 encode Lys15, Lys16, Arg17 and Arg18 as D-residues and leave the configuration of Ser1 undefined; this record therefore cites CID 16133751, which encodes the all-L chain.

• Registry number

  Two CAS numbers attached to epitalon

  A second registry number, 64082-79-7, also appears in the PubChem record; 307297-39-8 is carried here as primary.

• Registry record

  Structure and mass recorded for the copper complex

  Public databases do not agree on the complex: searching the name GHK-Cu in PubChem returns several distinct structures at 400.90, 401.91, 402.92, 403.92, 742.3 and 744.3, differing in how many protons the ligand has lost and in peptide-to-copper stoichiometry.

• Registry number

  GIP(1-42)'s CAS number resolves in GSRS but not in PubChem

  GSRS UNII 1O4H75S7H2 assigns primary CAS 100040-31-1 to the human 42-residue free peptide, while PubChem CID 131954558 matches its connectivity and formula but leaves all 46 atom stereocentres undefined.

• Registry number

  GLP-1(7-37)'s GSRS record cross-references an acetate CID, not the free peptide

  GSRS UNII PI470C66NT and primary CAS 106612-94-6 describe the free 31-residue peptide represented by PubChem CID 16133830, although the GSRS CID cross-reference points to acetate CID 91820613.

• Registry record

  A registry synonym missing one lysine

  A registry synonym for this substance omits a lysine while a correctly specified 28-residue synonym sits alongside it — do not regard every registry synonym as equally authoritative.

• Notation

  Mazdutide's position 9 in copies of the WHO lists

  Text extracted from WHO Proposed INN List 126 and Recommended List 88 gives Asp at position 9 in English, French and Spanish, but one indexed copy of List 88 gives Lys in French and Spanish; this record keeps Asp9, which its printed sequence also shows.

• Formula or mass

  One serine more or fewer between two registry structures

  The formula recorded here is the WHO-defined structure. PubChem's name-linked record reports C207H317N45O65, which differs by exactly one serine residue — C3H5NO2, 87.0320 Da.

• Sequence

  Residue 33 of oxyntomodulin: arginine or lysine

  PubChem CID 121494088 encodes the human 37-residue free peptide ending KRNRNNIA, whereas CID 16144019 ends KRNKNNIA and contains Lys33 in place of Arg33.

• Origin

  Where P021 came from: CNTF-derived or isolated from Cerebrolysin

  It is not described there as a chemically identified fragment isolated from Cerebrolysin, and that provenance claim should not be repeated.

• Chemical behaviour

  How the aggregation of pramlintide is described

  Pramlintide is widely described as non-aggregating. Exact-compound work reports it assembling into multimers and forming amyloid fibrils in vitro in a pH-dependent process…

• Sequence

  Thr and Lys order in candidate sequences from one paper

  Vanhee et al. (PMID 31667971) reports TKPRPGP and KTPRPGP as de novo candidates at 1.5 ppm. Arg-C digestion did not separate them; subsequent rLys-C digestion yielded the fragment pair consistent with TKPRPGP.

• Notation

  How semaglutide's position-8 residue is written

  WHO Proposed INN List 101 and Recommended List 63 print position 8 in English as 2-amino-2-propanoic acid, without the methyl that their French and Spanish names include; this record keeps Aib, 2-aminoisobutyric acid.

  The IUPHAR/BPS Guide to Pharmacology (ligand 9724, release 2026.3.1) prints Ala at position 8 in its sequence fields while its structure encodes Aib; FDA GSRS also records Aib there.

• Description

  Semax described as ACTH(4-7)-Pro-Gly-Pro or as an ACTH(4-10) analogue

  Much of the published literature instead describes Semax as an ACTH(4-10) analogue. Both descriptions refer to the same molecule…

• Residue count

  Sermorelin's length in the Guide to Pharmacology

  The IUPHAR/BPS Guide to Pharmacology (ligand 6998, release 2026.3.1) prints a thirty-residue sermorelin sequence ending Gln30; this record keeps the twenty-nine-residue fragment ending in Arg29 amide, matching PubChem CID 16132413.

• Residue count

  Length of SHLP6

  SHLP6 is twenty residues; descriptions that give all SHLPs a common length range are wrong.

• Registry record

  SHU9119's PubChem entry encodes a different structure

  PubChem CID 6440621, the entry titled Shu 9119 and the one its CAS number resolves to, encodes a different ring system; this record cites CID 9898183, which encodes the Asp2-Lys7 lactam with the same formula.

• Origin

  Survodutide: glucagon-based or an oxyntomodulin analogue

  Zimmermann et al. (PMID 36356832) describe survodutide as made by introducing modifications into the human glucagon sequence, whereas a review by Cabri et al. (PMID 34195230) calls it an oxyntomodulin analogue; this record follows the design paper.

• Registry number

  Two CAS numbers attached to tesamorelin

  A second registry number, 804475-66-9, also appears in the PubChem record; 218949-48-5 is carried here as primary.

Ac-SDKP (Goralatide)

• Name or substance

  Ac-SDKP vs thymosin beta-4 and TB-500

  Ac-SDKP is not thymosin beta-4 and not a generic TB-500 fragment. It is one specifically processed N-terminal tetrapeptide and is not a stand-in for the parent's other sequence regions.

alpha-MSH

• Name or substance

  alpha-MSH vs afamelanotide

  It is not afamelanotide: the parent retains Met4 and L-Phe7, and the analog's norleucine and D-phenylalanine substitutions must not migrate into the parent's identity fields.

• Name or substance

  alpha-MSH vs ACTH(1-13)

  Nor is it simply 'ACTH(1-13)' — the N-acetyl and C-amide processing distinguish it from an uncapped fragment.

Amylin (human IAPP)

• Name or substance

  Amylin, IAPP and related precursor and species names

  They are NOT synonyms for the IAPP gene, for proIAPP, for a processing intermediate, for the reduced peptide, or for rodent amylin — rat amylin differs in sequence and is a common substitute in structural work.

• Name or substance

  Amlintide vs pramlintide

  The FDA substance record uses 'amlintide' as a preferred name for this peptide; amlintide is NOT pramlintide, which carries three proline substitutions and is a separate entry in this library.

• Name or substance

  Receptor genes CALCR and CALCRL

  CALCRL is a different gene and must not be substituted for CALCR, and there is no standalone IAPP receptor gene to name.

Anamorelin

• Salt or form

  Anamorelin free base vs hydrochloride

  The CAS recorded here is the parent free base. The hydrochloride requires separate salt accounting; chloride is not part of this formula.

AOD-9604

• Name or substance

  AOD-9604 is not the same as "hGH fragment 176-191"

  …the unqualified name “hGH fragment 176-191” can instead denote the distinct native phenylalanine-starting peptide and is not used here as an interchangeable identity…

ARA-290

• Notation

  Pyroglutamate at position 1, not glutamine

  No oneLetter string is recorded: position 1 is pyroglutamate, and writing it as Q would denote glutamine, a different residue worth 17.03 Da more.

CJC-1295

• Registry identifier

  CJC-1295 with and without the drug affinity complex

  The name CJC-1295 is used in the literature and in commerce for two distinct species.

  PubChem CID 91971820, CAS 446262-90-4 and GSRS UNII 62RC32V9N7 identify the DAC form and are excluded from this non-DAC record. No CAS or UNII is published for the non-DAC species because none could be verified against a primary registry.

Cosyntropin (ACTH 1-24)

• Name or substance

  Cosyntropin, ACTH(1-24), vs other ACTH forms

  Cosyntropin is ACTH(1-24). It is not full-length ACTH(1-39), not ACTH(4-10), and not alpha-MSH.

Desmopressin

• Name or substance

  dAVP vs dDAVP

  The abbreviation dAVP is also used for its L-Arg8 counterpart and is not retained as an alias.

Elamipretide

• Salt or form

  Elamipretide vs its trihydrochloride salt

  The parent registry identifiers do not identify the trihydrochloride salt.

• Name or substance

  SS-31 vs SS-02

  Equal formula and mass do not distinguish SS-31 from the differently ordered SS-02 peptide.

Examorelin (Hexarelin)

• One substance, two names

  Examorelin and hexarelin: one substance, two names

  Examorelin and hexarelin are one substance under two names, not two entries.

• Name or substance

  Examorelin vs "methylated GHRP-6"

  Its relationship to GHRP-6 is a single methyl group — a net CH2, 14.0157 Da — but 'methylated GHRP-6' is insufficient identity information unless the methyl position is retained.

Galanin (human 1-30)

• Name or substance

  Human galanin vs 29-residue galanins of other species

  Human galanin is thirty residues with a free acid terminus and is NOT interchangeable with the 29-residue amidated galanins from other species that appear throughout this literature as comparators…

• Name or substance

  Galanin vs galanin-like peptide

  Galanin-like peptide is a different molecule, not an alias.

• Name or substance

  Spexin is not a fragment of galanin

  And spexin is not a proteolytic fragment of galanin — the two are separate gene products that happen to share receptors.

GHK (Prezatide)

• Registry identifier

  GHK and GHK-Cu: two substances, two CAS numbers

  The free tripeptide and the copper complex are distinct molecular records with different formulas, masses, and registry numbers: the free peptide is CAS 49557-75-7 (INN prezatide), and the copper complex is CAS 89030-95-5 (prezatide copper).

  …certificates of analysis in this market have carried the free-tripeptide number on copper-complex product, which describes the wrong substance.

• Name or substance

  GHK, GHK-Cu and Pal-GHK

  GHK, GHK-Cu and Pal-GHK are three different substances: an uncomplexed peptide, a copper coordination species, and a covalently lipidated derivative.

  Pal-GHK is also not GHK-Cu with a delivery modification bolted on: acylating the N-terminal amine alters a group that participates in GHK's copper coordination…

GHRP-6

• Registry identifier

  GHRP-6 vs GHRP-2 on a PubChem record with the same formula

  A separate PubChem record for the same formula and mass carries a synonym belonging to GHRP-2, a different peptide; identity should be established against CAS 87616-84-0 rather than by name matching alone.

  GHRP-2 is not GHRP-6; they are different hexapeptides.

GIP(1-42)

• One substance, two names

  "Gastric inhibitory polypeptide" is GIP

  …'Gastric inhibitory polypeptide' is the historical name for this same hormone, not a different peptide.

• Name or substance

  Human GIP(1-42) vs porcine GIP and shorter GIP forms

  …human GIP differs from porcine at residues 18 and 34. Full-length GIP must not be merged with GIP(3-42), GIP(1-30)amide, or proGIP — DPP-IV cleavage changes the molecule and its pharmacology.

GLP-1(7-36) amide

• Name or substance

  GLP-1(7-36) amide vs GLP-1(7-37)

  …'GLP-1(7-36)' without an amidation designation is not sufficiently specified. This entry is the AMIDATED form; GLP-1(7-37) is a separate molecule with an additional terminal glycine and a free carboxyl…

  GLP-1(1-37) is the N-terminally extended proform and is not this hormone…

  Thirty-one residues ending in glycine with a FREE C-terminal carboxyl. Distinct from both the amidated 30-residue form and from GLP-1(1-37).

• Name or substance

  "Insulinotropin" names GLP-1(7-37), not the 7-36 amide

  The name Insulinotropin belongs to GLP-1(7-37) and is recorded on that entry; it is not an alias of this amidated form.

  Mojsov et al. (PMID 3543057) named this glycine-extended form Insulinotropin; the name does not denote the amidated GLP-1(7-36) form.

Glucagon

• Name or substance

  Glucagon vs proglucagon, GLP-1 and oxyntomodulin

  Glucagon, GLP-1 and oxyntomodulin are related through processing of a shared precursor but are not aliases.

  Oxyntomodulin is ONE peptide, not a mixture of GLP-1 and glucagon. It is also not glicentin, which is a larger processing product that contains the oxyntomodulin region…

Gonadorelin (GnRH-I)

• Name or substance

  GnRH-I vs GnRH-II and synthetic analogs

  GnRH-I is not GnRH-II and not any of the long-acting synthetic GnRH analogs; a generic 'GnRH' label does not identify this decapeptide.

• Name or substance

  GnRH is not cleaved from kisspeptin

  Kisspeptin does not become GnRH by cleavage — they are different sequences acting at different receptors, connected by a neuronal circuit.

hCG (Human chorionic gonadotropin)

• Name or substance

  What the name "hCG" covers

  Names of the individual subunits, and of the genes that encode them, are not names of the intact hormone and are not aliases of this record.

HNG ([Gly14]-Humanin)

• Name or substance

  Humanin vs HNG, HNGF6A and the MTRNR2L gene names

  N-formyl humanin is a distinct chemical form. MTRNR2L gene names denote nuclear loci and are not peptide aliases.

  …'Humanin-G' denotes substitution at position 14, not a glycine extension.

  HNGF6A is not an alias of humanin or HNG. F6A-humanin alone is a third molecule again — it retains Ser14.

Human GLP-2(1-33)

• Name or substance

  What the name "GLP-2" covers

  …on its own specifies neither species nor whether a peptide is intact or shortened, so this record keeps the human (1-33) form explicit.

Human Octanoyl-Ghrelin

• Name or substance

  What the unqualified name "ghrelin" can mean

  …'Ghrelin' alone is not a resolved chemical identity. Species, chain length, acylated versus desacyl, and the acyl chain itself must all be specified.

  Desacyl-ghrelin is a different substance, not the same one differently formulated.

Humanin (HN)

• Name or substance

  Humanin: standard-code form vs mitochondrial-code prediction

  This record specifies the 24-residue standard-code form; a mitochondrial-code prediction is a distinct sequence.

Kisspeptin-14

• Name or substance

  Kisspeptin-14 vs the 13- and 10-residue kisspeptins

  Removing its initial aspartate gives the 13-residue sequence; removing DLPN gives the 10-residue sequence. These are different molecular forms even where receptor responses are similar.

KPV

• Salt or form

  Free KPV vs N-acetylated, C-amidated KPV

  Because commercially supplied material may be acetylated at the N-terminus and amidated at the C-terminus, identity methods must establish which form is present.

KTTKS (Pentapeptide-4)

• Name or substance

  Matrixyl (palmitoyl-KTTKS) vs unmodified KTTKS

  The palmitoyl modification dominates the lipophilicity of the molecule and is part of its declared identity; an unmodified KTTKS preparation is a different substance with a different mass.

  KTTKS is not Matrixyl. Matrixyl is the palmitoylated derivative, Pal-KTTKS, and N-palmitoylation adds C16H30O — 238.2297 Da — changing both the covalent structure and the physicochemical behaviour. 'Pentapeptide-4' alone does not distinguish them…

Macimorelin

• Salt or form

  Acetate salt vs a covalent N-acetyl group

  Acetate in a salt preparation must not become a covalent N-acetyl modification in the structural record.

  Acetate salt terminology does not establish covalent N-acetylation.

  Acetate salt terminology does not establish covalent N-acetylation.

Matrixyl

• Name or substance

  Palmitoyl pentapeptide-3 and palmitoyl pentapeptide-4

  …the material has also been designated palmitoyl pentapeptide-3 under earlier INCI naming. Identity should be established against CAS 214047-00-4.

Mazdutide

• Name or substance

  Survodutide vs mazdutide

  Survodutide and mazdutide are both GLP-1/glucagon dual agonists and are not interchangeable: they differ in main-chain sequence, nonstandard residue, conjugation position, linker and lipid.

  Survodutide and mazdutide share a receptor profile and are not chemically interchangeable.

• Notation

  Ac4c vs Aib at position 2

  Position 2 is Ac4c, 1-aminocyclobutane-1-carboxylic acid. It is NOT Aib. The two differ by one carbon, 12.0000 Da exactly, and substituting one for the other imports the chemistry of a different peptide.

  Position 2 is Aib, 2-aminoisobutyric acid — not Ac4c, which is what survodutide carries.

• Name or substance

  Glucagon-derived vs oxyntomodulin-derived

  Zimmermann et al. (PMID 36356832) describe survodutide as made by introducing modifications into the human glucagon sequence, whereas a review by Cabri et al. (PMID 34195230) calls it an oxyntomodulin analogue; this record follows the design paper.

  Being oxyntomodulin-derived is not permission to substitute oxyntomodulin's sequence or another dual agonist's data.

  …'oxyntomodulin-like' is a description of GLP-1R/GCGR pharmacology and does not establish oxyntomodulin-derived chemistry; a compound can have that pharmacology from a different scaffold entirely.

Melanotan I (Afamelanotide)

• Name or substance

  Melanotan I vs Melanotan II

  The unqualified word melanotan is not a usable identity field. Melanotan II is this cyclic lactam analog; Melanotan I is afamelanotide, a linear thirteen-residue peptide with a different formula and mass.

  Most importantly, Melanotan I is NOT Melanotan II — this is a linear thirteen-residue analog, that is a cyclic lactam heptapeptide, and they differ in formula and mass.

• One substance, two names

  Melanotan I and afamelanotide: one peptide, two names

  Melanotan I and afamelanotide are the same defined peptide. One name is commercial, the other the standardised substance name; they are not two different sequences.

Melanotan II

• Name or substance

  Melanotan II vs PT-141: C-terminal amide vs free acid

  A check that asks only whether a signal appears near 1024.5 is therefore satisfied by either compound…

  …material sold as PT-141 is not shown to be PT-141 rather than Melanotan II by a single rounded mass, by retention time on a method never demonstrated to resolve the pair, or by a purity figure.

MOTS-c

• Salt or form

  Trifluoroacetate salt record vs the free peptide

  PubChem CID 146675088 contains no counterion component and reports C101H152N28O22S2 for the free peptide, so a counterion-containing preparation requires a separately specified composition.

N-Acetyl Selank Amidate

• Name or substance

  "N-acetyl Selank" without the amidate

  A bare N-acetyl Selank label does not specify the C-terminal group and is not an alias here.

• Registry identifier

  Identifiers that belong to N-acetyl Selank free acid

  PubChem CID 133082488 and UNII J3PM702O93 describe the N-acetyl Selank free acid, C35H59N11O10, and are not identifiers for this amidate.

N-Acetyl Semax Amidate

• Name or substance

  "N-acetyl Semax" without the amidate

  A bare N-acetyl Semax label does not specify the C-terminal group and is not an alias here.

P021 (P21)

• Notation

  "AG" in Ac-DGGLAG-NH2 is one adamantane unit

  …the shorthand Ac-DGGLAG-NH2 appears in the primary literature, where AG denotes a single adamantane-derived unit — NOT alanine followed by glycine. Parsed as an ordinary six-residue peptide it yields the wrong molecule, formula and mass.

Pal-GHK (Palmitoyl Tripeptide-1)

• Name or substance

  "Palmitoyl oligopeptide" names more than one peptide

  …'Palmitoyl oligopeptide' is not a unique identifier and should be kept only as a qualified alias; it is used for other lipidated peptides too.

PE 22-28

• Name or substance

  PE 22-28 is not a fragment of spexin

  This entry previously described PE 22-28 as residues 22 to 28 of spexin and carried the alias Spexin (22-28). That was wrong…

  The PE in the name denotes the sortilin PROPEPTIDE, and 22 to 28 are its residue positions within that propeptide — not within any peptide called PE.

  Spexin and spadin are unrelated peptides. Mature spexin has fourteen residues, and PE 22-28 is derived from the sortilin propeptide. The former alias Spexin (22-28) incorrectly assigned that fragment to spexin.

Pralmorelin (GHRP-2)

• Name or substance

  "GHRP" does not mean a GHRH-receptor ligand

  And GHRP does not denote a GHRH-receptor ligand — the similar names refer to GH secretion, not a shared receptor.

Pramlintide

• Name or substance

  Pramlintide vs human and rat amylin

  Pramlintide is not another name for human amylin and not identical to rat amylin. It differs from human amylin at exactly three positions: A25P, S28P, S29P.

  Its native amylin comparator is rat amylin, whose sequence differs from human amylin; those comparator data are not evidence for the human-amylin sequence.

• Salt or form

  Pramlintide CAS number: peptide vs acetate salt record

  The CAS recorded here is the peptide; a pramlintide acetate record describes a salt and must not replace this identity.

Selank

• Name or substance

  Selank vs N-acetyl Selank amidate

  The catalog separately lists N-acetyl selank amidate, a distinct molecule carrying an N-terminal acetyl group and a C-terminal amide.

Semax

• Name or substance

  Semax vs N-acetyl Semax amidate

  The catalog separately lists N-acetyl semax amidate, which carries an N-terminal acetyl group and a C-terminal amide; that is a distinct molecule with a different formula, mass, and registry number, and it is not covered by this record.

Sermorelin

• Name or substance

  Sermorelin and tesamorelin share residues 1 to 29

  Sermorelin and tesamorelin have identical residues at positions 1 to 29…

Setmelanotide

• Name or substance

  Disulfide ring vs lactam ring in cyclic melanocortin peptides

  This is not a head-to-tail ring and not an Asp-Lys lactam — the distinction from the Melanotan II scaffold is the point of the entry.

SHLP2

• Name or substance

  SHLPs are not humanin fragments

  …'Humanin-like' describes the genomic neighbourhood, not the sequence: SHLP2 is not a humanin fragment and shares no substantial sequence with it.

  The number denotes a distinct peptide, not an activity rank and not a shortened humanin.

  It is neither a truncated humanin nor interchangeable with SHLP2 or SHLP3, and it does not behave like them…

• Name or substance

  SHLP2 vs the K4R-SHLP2 variant

  K4R-SHLP2 is a distinct variant arising from a mitochondrial single-nucleotide polymorphism and is not an alias for this Lys4 form.

Spadin

• Name or substance

  Spadin: seventeen or eighteen residues

  This entry specifies the eighteen-residue Tyr-extended form; the unqualified name spadin and the label PE(12-28) do not resolve the seventeen-versus-eighteen-residue distinction.

Spexin

• Name or substance

  NPQ: precursor or mature spexin

  NPQ is a discovery-era designation that may refer to the precursor; it does not by itself identify the mature amidated peptide.

TB-500

• Name or substance

  "TB-500" does not name one structure

  TB-500 is a product designation whose use does not uniquely specify a molecular structure. This dossier concerns the acetylated LKKTETQ referent identified in analytical literature.

THIQ

• Name or substance

  THIQ the compound vs THIQ the chemical class

  The generic scaffold and this defined MC4R agonist are not the same substance, and a name-only search imports unrelated chemistry — at least one supplier listing conflates them.

• Salt or form

  The chlorine in THIQ's formula is not a hydrochloride

  The chlorine in the formula is a covalent aryl chloride, NOT evidence of a hydrochloride salt.

Thymosin alpha-1

• Name or substance

  Thymosin alpha-1 vs the beta-thymosins

  The shared historical thymosin designation does not establish a common structural family with beta-thymosins.

Thymosin beta-4

• Name or substance

  TB-500 is not thymosin beta-4

  TB-500 is not this molecule. That name designates a distinct seven-residue fragment, carried separately in PubChem as CID 62707662 with a molecular mass of approximately 889 daltons, against 4963.5 daltons for the full-length peptide described here…