Comparison
GHK-Cu vs TUDCA
Side-by-side of GHK-Cu and TUDCA. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
GHK-Cu
GHK-Cu peptide (glycyl-L-histidyl-L-lysine copper) is a topical copper peptide. Trials show fine-line and wound-healing gains; injectable longevity claims rem.
TUDCA
TUDCA is the taurine-conjugated form of ursodeoxycholic acid, a bile-acid molecule with replicated effects on liver function, ER stress, and bile flow.
Effects at a glance
GHK-Cu
- •Endogenous tripeptide that binds copper(II); plasma levels decline ~60% from age 20 to 60
- •Topical RCTs show improvement in skin firmness, fine lines, and barrier function over 12 weeks
- •Wound-healing models report accelerated re-epithelialization in diabetic and aged skin
- •Pickart gene-expression analyses show reset of >4000 genes toward a younger expression profile in cell culture
- •Anecdotal subcutaneous longevity protocols use 1 to 3 mg daily; no human longevity RCTs exist
- •Hair-growth claims rest on small open-label trials and topical scalp formulations
TUDCA
- •Bile-acid molecule (taurine-conjugated UDCA) with chemical chaperone activity at the endoplasmic reticulum
- •Established pharmaceutical use for cholestasis and primary biliary cholangitis at 500-750 mg/day
- •Reduces ER stress and stabilizes misfolded proteins; the mechanistic basis for emerging ALS / retinal applications
- •Modest improvements in NAFLD markers and insulin sensitivity at 500-1,750 mg/day in small trials
- •Mitochondrial protection signal in animal models drives the longevity-supplement positioning
- •Generally well-tolerated; mild GI effects are the main dose-dependent issue
Side-by-side
| Attribute | GHK-Cu | TUDCA |
|---|---|---|
| Category | peptide | supplement |
| Also known as | Copper Peptide, Glycyl-L-histidyl-L-lysine copper, GHK | tauroursodeoxycholic acid, taurine-conjugated UDCA |
| Half-life (hr) ↗ | 0.5 | 4 |
| Typical dose (mg) ↗ | 2 | 500 |
| Dosing frequency | daily | daily, divided into 2 doses with food |
| Routes | topical, subcutaneous | oral |
| Onset (hr) | 24 | 1 |
| Peak (hr) | 168 | 2 |
| Molecular weight | 340.85 | 499.7 |
| Molecular formula | C14H24N6O4 (GHK alone); C14H22CuN6O4 with Cu(II) | C26H45NO6S |
| Mechanism | Tripeptide that chelates Cu(II) and delivers it to copper-dependent enzymes (lysyl oxidase, superoxide dismutase). Modulates expression of >4000 genes toward a younger profile in fibroblast culture, including upregulation of decorin and downregulation of pro-inflammatory cytokines. | Bile-acid signaling via FXR/TGR5 receptors; chemical chaperone reducing ER stress and unfolded protein response; mitochondrial protection through reduced outer-membrane permeabilization. |
| Legal status | Topical cosmetics legal in most jurisdictions; injectable form not FDA approved for any indication; research-use-only grey market | OTC dietary supplement (US); pharmaceutical in Italy and several Asian countries |
| WADA status | allowed | allowed |
| DEA / Rx | Topical OTC (cosmetic); injectable not FDA approved; research-chemical status | OTC supplement |
| Pregnancy | Insufficient data; topical use likely low-risk; injectable not recommended | Insufficient data for supplement use; UDCA used in cholestasis of pregnancy |
| CAS | 49557-75-7 | 14605-22-2 |
| PubChem CID | 73587 | 9848818 |
| Wikidata | Q3104638 | Q418751 |
Safety profile
GHK-Cu
Common side effects
- mild erythema at topical site
- transient itch
- blue-green discoloration of injection site (copper)
- rare contact dermatitis
Contraindications
- copper allergy
- Wilson disease
- open wound near injection site (caution)
- pregnancy (no data)
Interactions
- topical retinoids: additive irritation; alternate days or apply at different times(minor)
- topical vitamin C (ascorbic acid): ascorbate reduces Cu(II) to Cu(I), which can destabilize the GHK-Cu complex; separate by 30 minutes(minor)
TUDCA
Common side effects
- mild GI upset
- diarrhea (dose-dependent)
- constipation (rare)
- nausea
Contraindications
- complete biliary obstruction
- pregnancy / lactation (insufficient supplement-dose data)
- active GI disease without medical supervision
Interactions
- cyclosporine, oral contraceptives, fat-soluble vitamins: modest absorption changes via altered bile-acid pool(minor)
- phenylbutyrate: synergistic for ALS use (Relyvrio combination); consult clinician(moderate)
Which Should You Take?
TUDCA comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. GHK-Cu is the right call when one of the conditionals below applies.
- → If your priority is skin health, pick GHK-Cu.
- → If your priority is wound healing, pick GHK-Cu.
- → If your priority is liver function, pick TUDCA.
- → If your priority is mitochondrial function, pick TUDCA.
Edge case: If you want to avoid research-only / gray-market sourcing, TUDCA is the more accessible choice.
Default choice: TUDCA. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for GHK-Cu only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between GHK-Cu and TUDCA?
GHK-Cu and TUDCA differ in category (peptide vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, GHK-Cu or TUDCA?
GHK-Cu half-life is 0.5 hours; TUDCA half-life is 4 hours.
Can you stack GHK-Cu with TUDCA?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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