SkinGly-His-LysTripeptide-1

GHK (copper-free, Gly-His-Lys)

Endogenous copper-binding tripeptide matrikine · the bare, copper-FREE ligand · the famous biology belongs to GHK-Cu

GHK is a small, naturally occurring tripeptide — glycine-histidine-lysine — found in human plasma, where its defining property is an exceptionally tight grip on copper. This page is specifically about the bare, copper-FREE peptide, which is sold as a cosmetic ingredient and reconstituted as an injectable research compound; the copper complex GHK-Cu has its own separate entry, and the distinction is the entire point. Almost all of the celebrated GHK biology — the collagen stimulation, wound healing, skin remodelling and the headline 'gene-resetting' claims — was actually studied using GHK-Cu, the copper complex, not the free peptide. The originating researchers themselves are explicit on this: in their own words, virtually all biological GHK effects require copper bound to the tripeptide (Pickart, PMID 28212278). That single fact reframes the injectable narrative: administered free GHK is a copper-delivery vehicle — it scavenges Cu²⁺ from the body's own pool and converts to GHK-Cu in vivo, which means its regenerative value depends entirely on copper availability. The famous '4,000 genes / 31% of the genome' figure is a database (Connectivity-Map) analysis by the originators, done in cell lines, not a demonstrated effect of copper-free GHK in people. There is no confirmed independent randomized trial of copper-free GHK, and the often-cited 2002 facial-cream study is an unindexed conference abstract that used the copper complex. The fair framing: a real endogenous peptide with genuine copper-binding chemistry, whose regenerative reputation lives on the GHK-Cu page and depends on the copper this page's molecule scavenges and binds rather than carries pre-formed.

The short version

GHK is a tiny natural peptide made of three amino acids — glycine, histidine and lysine — that your body already carries in the blood. Its standout trait is that it grabs onto copper very tightly. This page is about the plain, copper-free version. There is a separate page for GHK-Cu, the copper-attached version, and keeping the two apart is the whole reason this page exists.

Here is the key thing most marketing skips: nearly all of the famous GHK research — the collagen-building, wound-healing, skin-rejuvenating and 'switches thousands of genes' studies — was done with the copper version, GHK-Cu, not the bare peptide. The scientists who discovered and championed GHK say plainly that copper is needed for basically all of its effects. So when a product sells 'copper-free GHK' and points to those impressive results, it is borrowing the copper version's evidence for a different molecule.

There is a chemical wrinkle that actually makes the injectable story more coherent: in a copper-containing body, free GHK does not stay copper-free. It scavenges available copper and converts to GHK-Cu right there in tissue. So the injected free peptide is really a copper-delivery vehicle — its value depends entirely on how much copper your body has available for it to grab.

What is honest: a real, naturally occurring peptide with genuine copper chemistry, whose glamorous regeneration story belongs to GHK-Cu and depends on the very copper this molecule scavenges and binds rather than arriving pre-attached.

Molecular identity

Specs

Molecular weight: 340.38 g/mol (free peptide)
Molecular formula: C₁₄H₂₄N₆O₄ (free peptide)
Monoisotopic mass: 340.18590 Da

Sequence: Gly-His-Lys (glycyl-L-histidyl-L-lysine) — 3 AA, N-to-C tripeptidePubChem CID 73587
Structure / class: Endogenous copper-binding tripeptide (matrikine); the apo/metal-free ligand of GHK-CuPubChem; copper-peptide literature
CAS / UNII: 49557-75-7 · 39TG2H631E (free peptide; distinct from the GHK-Cu complex CAS 89030-95-5)PubChem CID 73587
PubChem CID: 73587PubChem (free peptide; NOT the copper-complex CIDs)
Water solubility: Freely water-soluble; highly hydrophilic (computed XLogP −4.4, TPSA 176 Å²)PubChem CID 73587 (computed properties)
Copper coordination: Apo ligand — carries no copper itself; binds one Cu²⁺ via the imidazole N + N-terminal amine to form GHK-Cu in vivoCopper-peptide coordination chemistry; PubChem (separate complex record)
Molecular target: No classic receptor — acts as a copper(II)-binding/transport ligand (matrikine); the studied biology belongs to the GHK-Cu complexCopper-peptide literature; PMID 28212278
Relationship to GHK-Cu: Copper-free ligand; binds Cu²⁺ in vivo and converts to GHK-Cu — most studied GHK biology used the copper complexCopper-peptide literature; PubChem (separate records)
Half-life: Not established for free GHK (no published human pharmacokinetics)Not established
Regulatory status: Cosmetic ingredient (INCI Tripeptide-1), not a drug; not FDA-approved for any therapeutic claimINCI; no NDA/BLA record located

Plain English

Mechanism

GHK is both a matrikine — a small matrix-derived peptide signal — and, above all, a copper carrier. Its defining biochemical property is an exceptionally high affinity for the copper(II) ion, and the originator literature's central claim is that GHK's biological activity operates through the copper it chelates: the peptide acts as a copper-delivery vehicle to cells, and in most assays the active species is GHK-Cu, not the bare peptide. This is the crux of the copper-free-versus-complex distinction and the reason this page exists separately from the GHK-Cu entry.

The honesty anchor is a direct statement from the discoverers. In their 2017 gene-expression paper, the originating group writes that virtually all biological GHK effects require copper(II) chelated to the tripeptide (PMID 28212278). That is the people who built the field saying copper is required — which directly undercuts marketing that presents copper-free GHK as carrying the same activity. The downstream effects usually attributed to 'GHK' — stimulation of collagen, elastin and glycosaminoglycan synthesis in fibroblasts, modulation of matrix-remodelling enzymes, angiogenesis and nerve outgrowth, antioxidant and anti-inflammatory activity — are overwhelmingly GHK-Cu findings, mostly in vitro and mostly from the originator group.

There is a further chemical wrinkle: in a copper-containing biological environment, administered 'copper-free' GHK will scavenge available copper and become GHK-Cu, so even the premise of a distinct copper-independent therapy is shaky. No robust body of evidence isolates a unique, copper-independent therapeutic mechanism for the bare peptide. What can be said cleanly is that free GHK is an endogenous, copper-binding plasma matrikine whose main role is as the ligand that delivers copper — the active, studied form being the complex on the other page. This is also why copper availability is the headline cofactor for the injected free peptide: the biology depends on it.

Sources:PMID 28212278 PMID 3169264 PMID 26236730

Why people reach for it

Potential benefits

GHK is reached for on the same skin- and tissue-remodeling goals as its copper complex — with the honest caveat that the famous biology belongs to GHK-Cu, and free GHK depends on the copper it scavenges to reach that active form. Here's what draws people to it.

Skin remodeling and collagen signaling — Its headline draw. Once free GHK binds copper and becomes GHK-Cu, it signals fibroblasts to build collagen and the skin's matrix — the basis for its anti-aging reputation (a GHK-Cu finding, mostly in-vitro/topical, not proven for the bare peptide as an injection).
A copper-delivery vehicle — Free GHK's distinctive role: it grips copper exceptionally tightly and converts to GHK-Cu in the body, so it's reached for as a way to deliver copper to tissue where it feeds collagen cross-linking — its value rising and falling with copper availability.
Tissue repair and wound context — The copper complex it forms is studied for promoting skin regrowth and new blood vessels in wound models, which is why GHK is pursued around healing and connective-tissue recovery (reported for GHK-Cu, mostly preclinical).
A remodeling base that stacks well — It pairs cleanly with its own pre-formed complex GHK-Cu and with repair peptides from other angles — most commonly BPC-157 and TB-500 for a fuller tissue-repair push.

Sources:PMID 3169264 PMID 26236730 PMID 28212278

What people reach for GHK for, drawn from the copper-complex skin-remodeling literature it converts into and how it's used — not proven outcomes for the copper-free peptide. The originators state copper is required for virtually all GHK effects, and there is no confirmed independent trial of copper-free GHK. No medical claims.

Implied timing

Best time to dose

Implied best time

Evening

Most people take GHK in the evening, lining the skin- and tissue-remodeling signal up with the body's overnight repair window (morning is also fine).

GHK's documented effect (via the GHK-Cu it forms) is matrix remodeling — signaling fibroblasts to lay down collagen and elastin — and the skin and connective tissue do most of that rebuilding overnight during sleep, so an evening dose puts the signal in as that repair window opens.
It works as a remodeling/copper-delivery signal rather than an acute stimulant, so there's no wakefulness reason to favor the morning; aligning it with the overnight repair phase is the more mechanism-consistent lean.
No human pharmacokinetics or half-life exists for free GHK, so the timing is reasoned from its remodeling mechanism — not a measured duration of action. A consistent daily time matters more than the exact hour; morning works too.

No study establishes an ideal time of day for GHK — this is reasoned from its skin- and tissue-remodeling mechanism and how it's used. As a rule of thumb most peptide dosing lands in the midday-to-evening window; for GHK the lean is evening, to align with overnight repair.

How to run it

Dosing & protocol

GHK is reconstituted and injected subcutaneously — the form sold as a research peptide and the route the on-page calculator is built for. Community convention runs 500 mcg–2 mg/day SC. Read the numbers below as a map of how people actually use injectable free GHK — not a validated prescription, and not a route any published human trial supports.

Community convention, not trial-proven: injectable free GHK has no controlled human trial and no published pharmacokinetics. Its regenerative value depends on copper availability — free GHK converts to GHK-Cu in vivo, so the effective dose is partly a function of how much systemic copper is available to bind. Almost all foundational reviews are authored by Pickart, the molecule's discoverer. Every number here is a usage pattern, not evidence.

Tiered dose ranges

Community protocols scale the subcutaneous dose to the goal — introductory skin support or higher-end tissue remodeling.

Low / introductory:: 500 mcg once daily — first testing tolerance, or a conservative skin-support dose.
Standard:: 1 mg (1,000 mcg) once daily — the most common community maintenance dose for skin remodeling and collagen-signaling goals.
Higher end:: 1.5–2 mg/day — the top of the community range; sometimes split into two 750–1,000 mcg injections. No data establishes additional benefit over 1 mg.

Subcutaneous administration

GHK is injected into subcutaneous fat; site rotation and timing are the actionable choices.

Injection site:: Abdomen (staying a few centimeters from the navel), outer thigh, or love-handle area. Rotate sites between doses to prevent local irritation and lipohypertrophy (fatty lumps from repeated use of one spot).
Measuring the dose:: Drawn on a U-100 insulin syringe from the reconstituted vial. At the standard mix (10 mg vial + 2 mL BAC water = 5,000 mcg/mL): 500 mcg = 10 IU · 1,000 mcg = 20 IU · 1,500 mcg = 30 IU. The on-page calculator handles any vial size.
Time of day:: No peptide-specific timing data exists for injectable GHK. Most users lean evening to align the remodeling signal with the overnight repair window — see Best time to dose above — though morning is also fine; a consistent daily time matters more than the exact hour. If splitting a larger dose, space approximately 12 hours apart.
Food window:: Subcutaneous injection does not compete with food for absorption. Inject independent of meals.

Cycle & washout

GHK is typically run in defined cycles rather than indefinitely — consistent with how most peptides in this class are used.

Standard cycle:: 8–12 weeks of daily dosing, then reassess. Some users run shorter 4–6 week blocks.
Washout:: 4-week break between cycles. No GHK-specific receptor desensitization data exists; the washout is by convention, not demonstrated necessity.
On-demand use:: Some use GHK in shorter 2–4 week skin-focused pulses (around a procedure, season change, or healing period) rather than a fixed cycle.

Reconstitution at a glance

The on-page calculator does this live; the quick reference for a standard 10 mg vial:

Mixing:: 10 mg vial + 2 mL bacteriostatic water = 5,000 mcg per mL. On a 100-unit (1 mL) insulin syringe: 500 mcg = 10 IU · 1,000 mcg = 20 IU · 1,500 mcg = 30 IU · 2,000 mcg = 40 IU.
Why 2 mL:: A 2 mL dilution keeps the concentration at a manageable level for subcutaneous dosing in the low-milligram range — dose increments fall neatly on syringe markings.

Sources:PMID 28212278 PMID 3169264 PMID 26236730

Substrate the signal needs

Nutritional cofactor precision

GHK's mechanism is copper-delivery first. The headline cofactor is not a generic supplement — it is copper itself, because copper availability is what converts free GHK into GHK-Cu, the active complex that does the collagen and skin-remodeling work. Everything else follows from what activated GHK-Cu then signals for.

Reasoned from GHK's copper-ligand mechanism and collagen-synthesis biology — not a GHK cofactor study. Supplement doses are standard nutritional ranges; the copper/zinc balance point is especially important here because zinc and copper compete for intestinal absorption.

Copper — the activating cofactor (not optional)

This is not a generic 'trace mineral' point. Copper is what turns free GHK into GHK-Cu. Without adequate copper, injected free GHK has nothing to bind and the active complex does not form.

Mechanism:: By textbook coordination chemistry, GHK grips a single Cu²⁺ ion via its histidine imidazole and N-terminal amine to form GHK-Cu — the species the originator literature identifies as doing virtually all of the regenerative work. Administered free GHK is a copper scavenger; it will preferentially pull copper from available plasma and tissue pools to form that complex in vivo. Maintaining copper status is therefore the primary lever for making injectable free GHK active.
Dose & timing:: 1–2 mg elemental copper daily from food (liver, shellfish, legumes, nuts, dark chocolate are copper-dense) is the baseline. Supplemental copper bisglycinate 1–2 mg with a meal is a practical option if diet is genuinely copper-sparse — but food-first is preferred because whole-food copper comes with the cofactors (ceruloplasmin, etc.) that govern its handling.

Collagen substrate — vitamin C, hydrolyzed collagen, glycine/proline

Once GHK-Cu forms and signals fibroblasts to synthesize collagen, the fibroblasts need raw materials. Signaling more collagen without supplying the building blocks is a half-measure.

Vitamin C — 500 mg daily:: Cofactor for prolyl and lysyl hydroxylase, the enzymes that stabilize collagen's triple-helix structure. Without adequate vitamin C, the collagen signal GHK-Cu sends cannot be fully executed. Take with a meal, any time of day.
Hydrolyzed collagen — 10–15 g daily:: Supplies the glycine-proline-hydroxyproline tripeptides fibroblasts reassemble into new collagen. Timing: with vitamin C for potential synergy.
Glycine / proline via diet:: Glycine is the most abundant amino acid in collagen (one-third of residues). Adequate protein from collagen-rich sources (broth, gelatin) or a glycine supplement (~3–5 g/day) reinforces the substrate pool without a separate product.

Zinc — with the copper-balance caveat

Zinc supports matrix metalloproteinase (MMP) activity — the remodeling enzymes that clear old collagen before new matrix is laid. But for a copper-dependent peptide, the copper/zinc ratio matters more than either dose alone.

Mechanism:: Zinc is a catalytic cofactor for MMPs, which are needed to break down old cross-linked collagen so that new matrix can be deposited. However, zinc and copper compete for intestinal absorption via the same divalent-metal transporter. High-dose zinc quietly depletes copper — and copper is the activating cofactor for this peptide. Running zinc without a copper anchor works against GHK's primary mechanism.
Dose & timing:: 15 mg zinc picolinate or bisglycinate daily, explicitly paired with 1–2 mg copper bisglycinate taken at the same time to prevent depletion. Balance matters here more than maximizing either mineral individually. Take with a meal, away from iron if possible.

Combinations + timing

Stacking notes + timing windows

GHK's most honest stack partner is its own copper complex. Beyond that, the best injectable pairings come at tissue repair from a different angle — vascularization, cell migration, structural rebuild — rather than doubling the collagen signal.

Community combinations reasoned from complementary mechanisms — not regimens studied head-to-head. Injectable free GHK itself has no human trial, so any stack is doubly unproven. Doses are community convention; 'reach for' describes where users go, not a proven indication.

GHK + GHK-Cu (GHK-Cu)

The copper-free / copper-loaded pair — the same tripeptide backbone in two copper states. Cross-reference the relationship honestly.

Why it works:: GHK-Cu is free GHK with copper pre-loaded. Running both means the pre-formed complex delivers active GHK-Cu immediately (topically or systemically), while free GHK scavenges additional copper from local tissue pools and converts on-site. The relationship between the two is the same molecule at different copper-binding states — not two independent mechanisms. The net effect is extended or complementary copper delivery, not a synergy between different pathways. Note the honesty axis on the GHK-Cu page: its robust evidence is topical and in-vitro; the injectable systemic use of either form is convention, not trial-proven.
The protocol:: Community pairings typically run GHK-Cu 1 mg + free GHK 500 mcg–1 mg SC daily, or alternate the two on different days. No comparative human data exists.
Outcome:: Reached for by users wanting to maximize tissue copper delivery and collagen-signaling coverage simultaneously — a dual-state approach to the same molecule, not a multi-pathway stack.

GHK + BPC-157

GHK signals the collagen matrix; BPC-157 heals the underlying tissue and builds the vascular supply — two different levers on the same repair job.

Why it works:: BPC-157 is studied for accelerating healing across gut lining, tendons, and wound tissue — it drives angiogenesis (growth of new blood vessels) and upregulates growth-factor signaling in injury sites. GHK-Cu (which free GHK becomes after copper binding) works a different lever: stimulating fibroblasts to synthesize the collagen and elastin that fill the repaired space. Together they address both scaffold (GHK/GHK-Cu) and blood supply and repair-signal (BPC-157) — complementary levers, not the same one twice.
The protocol:: Free GHK 1 mg + BPC-157 250–500 mcg, each subcutaneous once daily, rotated sites. Can be drawn separately or co-injected. Ensure copper status is adequate (see cofactor card above) so the free GHK converts to its active form.
Outcome:: The combination users reach for on skin aging, wound healing, and soft-tissue recovery where both matrix remodeling and vascular repair are goals.

GHK + BPC-157 + TB-500

The systemic tissue-repair trio — adds cell migration to the matrix-remodel and vascular-repair pair.

Why it works:: TB-500 (Thymosin β4) promotes the migration of repair cells — stem cells, endothelial cells, keratinocytes — into damaged tissue. BPC-157 brings the vascular support; GHK (converting to GHK-Cu via available copper) drives collagen and matrix synthesis in the space they open. Three distinct jobs, three different levers.
The protocol:: Free GHK 1 mg + BPC-157 250–500 mcg daily; TB-500 on its own loading schedule (commonly 5–10 mg/week loading for 4 weeks, then 2.5–5 mg/week maintenance). GHK and BPC-157 are typically daily; TB-500 is typically weekly or twice-weekly.
Outcome:: Reached for on broader soft-tissue, skin, and connective-tissue repair goals — post-procedure recovery, chronic tendon or fascial injury, systemic skin remodeling.

Reconstitution math

Reconstitution calculator

Calculated for a 1 mL U-100 insulin syringe (100 units/mL).

Peptide per vial

BAC water added

Desired dose

Units per dose

Draw to this mark on a U-100 syringe

Volume per dose: 0.2 mL
Doses per vial: 10
Concentration: 5 mg/mL

One vial lasts

Daily: 10 days
Every other day: 20 days
5×/week: 14 days

Research use only. Not for human consumption. Outputs are reference values based on research literature — verify all measurements independently.

From the studies

Side effects from research

As an endogenous peptide used topically, copper-free GHK is generally regarded as well tolerated, with local irritation or sensitivity the usual topical possibilities. There is no large long-term safety database for the bare peptide, and this page makes no medical claims.

The bigger honesty point here is about efficacy attribution rather than acute harm: the regenerative reputation belongs to GHK-Cu, the originators say copper is required, and there is no confirmed independent trial of copper-free GHK — so a regenerative or anti-aging benefit should not be assumed from the marketing of the bare peptide.

Gray-market raw material and the GHK/GHK-Cu labelling ambiguity add identity and purity risk independent of the molecule. The honest summary: low topical risk, with the real caveat being overstated, copper-borrowed benefit claims.

As reported in literature

Research dosing ranges

These are reference conditions from the GHK literature — shown separately so research data is never mistaken for a recommendation. The crucial caveat: the primary data used the copper complex GHK-Cu, not the copper-free peptide this page is about. They are laboratory and database conditions, not injected human doses. Read the table for which form was actually tested (almost always GHK-Cu) versus what copper-free products are marketed as doing — that gap, plus the originators' statement that copper is required, is the honest story.

Dose	Route	Model	Outcome	Sources:
10⁻¹²–10⁻⁹ M	In vitro (fibroblast culture)	Original collagen study — explicitly the copper complex GHK-Cu (Maquart 1988)	Stimulated collagen synthesis at very low concentrations; genuine primary research — but a GHK-Cu finding, not evidence for copper-free GHK	PMID 3169264
Database analysis	In silico / microarray (CMAP)	Connectivity-Map gene-expression analysis by the originators (Pickart 2014)	Reported GHK changed expression of ~31% of assayed genes — source of the '~4,000 genes' claim; database/in-vitro, labelled 'GHK', not a clinical property of copper-free GHK	PMID 25302294
1 µM	In vitro (PC3/MCF7 cell lines)	Gene-expression profiling; copper emphasized as required (Pickart 2017)	Cell-culture concentration for gene profiling; same paper states copper is required for 'virtually all' GHK effects — not a human injectable dose	PMID 28212278
Not established	Subcutaneous	Independent controlled human trial of copper-free GHK (literature search)	No confirmed independent RCT of copper-free GHK located; the often-cited 2002 cream trial is an unindexed conference abstract that used GHK-Cu — recorded absence, not a positive result	PMID 29986520

Quick answers

Frequently asked

Is copper-free GHK the same as GHK-Cu?

No — they are chemically distinct, and that difference is the whole point. GHK-Cu is the copper complex (it has its own page); this page is the bare, copper-free peptide. Almost all the famous GHK research used GHK-Cu, and the original researchers say copper is required for virtually all of GHK's effects.

Does copper-free GHK rebuild collagen and reverse aging?

Those claims trace to GHK-Cu studies and reviews, not to copper-free GHK. Attributing the copper complex's regenerative results to the bare peptide is unsupported — by the originators' own statement that copper is required.

What about the '4,000 genes / resets the genome' claim?

That comes from a gene-database (Connectivity-Map) analysis done in cell lines by the original researchers, labelled 'GHK.' It is an in-vitro/database finding, not a demonstrated effect of applying copper-free GHK to people.

If free GHK converts to GHK-Cu in the body, why not just use GHK-Cu?

That is a fair question. GHK-Cu is the pre-formed complex — you get the active form immediately. Free GHK is a copper scavenger that converts to GHK-Cu in vivo depending on available copper. Some users run both or alternate them. The GHK-Cu page carries the fuller evidence and practical framing for that route.

Is there a good clinical trial of copper-free GHK?

Not that could be confirmed. No independent randomized trial of copper-free GHK with hard endpoints was located, and the often-cited 2002 face-cream study is an unindexed conference abstract that actually used the copper complex.

Why does copper matter so much as a cofactor for this peptide?

Because free GHK's mechanism is copper delivery. The peptide grips a copper(II) ion to form GHK-Cu — the active species the originator literature says does essentially all of the regenerative work. If systemic copper is low, there is less for the injected free peptide to bind, and less GHK-Cu forms. That makes copper availability the primary determinant of how effective injectable free GHK is.

Primary sources

References

PMID 3169264Maquart FX et al., FEBS Lett 1988 — original in-vitro study: the tripeptide-copper complex GHK-Cu stimulated collagen synthesis in fibroblast cultures at very low concentrations (primary research; COPPER COMPLEX, not free GHK)
PMID 25302294Pickart L, Vasquez-Soltero JM, Margolina A, Biomed Res Int 2014 — 'GHK and DNA: Resetting the Human Genome to Health'; Connectivity-Map microarray analysis reporting GHK altered ~31% of assayed genes (source of the '~4,000 genes' figure); originator-authored, in-vitro/database
PMID 26236730Pickart L, Vasquez-Soltero JM, Margolina A, Biomed Res Int 2015 — review, 'GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration'; states GHK functions as a complex with copper(II) (GHK-Cu)
PMID 28212278Pickart L, Vasquez-Soltero JM, Margolina A, Brain Sci 2017 — gene-expression analysis + review; the honesty anchor: authors state 'virtually all biological GHK effects require copper 2+ chelated to the tripeptide'; CMAP profiles at 1 µM in cell lines
PMID 29986520Pickart L, Margolina A, Int J Mol Sci 2018 — review, 'Regenerative and Protective Actions of the GHK-Cu Peptide…'; synthesizes regeneration claims for the COPPER COMPLEX across skin/lung/bone/liver
PubChem CID 73587PubChem record — identity for the FREE peptide: CID 73587, C₁₄H₂₄N₆O₄, MW 340.38, CAS 49557-75-7, UNII 39TG2H631E. Note: PubChem's synonym list for CID 73587 is contaminated with copper-complex names (GHK-Cu, Prezatide); the complex is a distinct molecule (CAS 89030-95-5, separate CIDs)

Research use only · Not medical advice · Updated 2026-06-01