Comparison Centre
Two compounds, the same questions, no cherry-picking
Marketing compares compounds on whichever measure flatters them. This compares them on the same fields every time — including the awkward ones like how much human safety data exists. Every score here rates the evidence, not the compound: a higher number means stronger or more mature research, not that something is safer or works better.
Sharing keeps the two compounds you picked.
How to read these scores
Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.
- Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
- Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
- Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
- Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
- Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.
None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.
GHK-Cu
Decent cosmetic evidence on the skin, very different question when people inject it.
TB-500 / Thymosin beta-4
A genuine biological protein with real research history, and a separate online product that is not quite the same thing.
How far human research has progressed
GHK-Cu
Cosmetic human studies for topical use; no established systemic clinical useTB-500 / Thymosin beta-4
Preclinical for musculoskeletal claims; limited clinical study in narrow indicationsClaim-specific benefit evidence
A human exposure study or trial registration does not establish that the claimed benefit occurs.
GHK-Cu
Not separately assessed; see the full profile.TB-500 / Thymosin beta-4
Not separately assessed; see the full profile.Human research context
GHK-Cu
Cosmetic human studies for topical use; no established systemic clinical useTB-500 / Thymosin beta-4
Preclinical for musculoskeletal claims; limited clinical study in narrow indicationsHuman efficacy evidence strength
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
GHK-Cu
TB-500 / Thymosin beta-4
Preclinical (animal / lab) evidence strength
Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
GHK-Cu
TB-500 / Thymosin beta-4
Human safety evidence strength
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
GHK-Cu
TB-500 / Thymosin beta-4
Regulatory status (legal position, not proof it works)
GHK-Cu
Check jurisdiction-specific details in the profile.
Widely used as a cosmetic ingredient in topical skincare. Injectable systemic use is not an approved medical treatment, and FDA has treated injectable GHK-Cu as a bulk substance raising significant safety risks for compounding. That listing status changed during 2026 and the substance was covered by FDA's July 2026 advisory committee review.
TB-500 / Thymosin beta-4
Check jurisdiction-specific details in the profile.
Not an approved medicine for injury recovery. Thymosin beta-4 has been studied clinically in specific ophthalmic and wound contexts; 'TB-500' as sold online is typically a synthetic fragment marketed outside medical supply. FDA's Pharmacy Compounding Advisory Committee considered thymosin beta-4-related substances in July 2026 for possible inclusion on the 503A Bulks List. Its recommendations are non-binding: this is a compounding-policy process, not FDA drug approval, validation of efficacy claims or blanket legalisation. It is also prohibited in sport.
Common claims
GHK-Cu
- · Reduces wrinkles and improves skin firmness
- · Regrows hair
- · Systemic anti-ageing and wound healing when injected
TB-500 / Thymosin beta-4
- · Accelerates soft-tissue and tendon healing
- · Reduces scar tissue
- · Improves flexibility and recovery in athletes
How settled our evidence rating is
GHK-Cu
TB-500 / Thymosin beta-4
Cancer-related questions raised by the biology
These are theoretical or monitored questions raised by how a compound works. They are not evidence that it causes cancer.
GHK-Cu
Copper availability and angiogenesis both have roles in tumour biology, which makes systemic dosing a theoretical question worth flagging. There is no human evidence of cancer causation from GHK-Cu, topical or otherwise.TB-500 / Thymosin beta-4
Thymosin beta-4 promotes angiogenesis and cell migration, and elevated expression has been described in some tumour contexts. That is a mechanistic and observational concern worth naming honestly; it is not proof that administering it causes cancer in humans. There is no human evidence either way.What this adds up to, in plain English
GHK-Cu
Preliminary human observations exist, but they may not establish a treatment-attributable benefit.TB-500 / Thymosin beta-4
The interesting work is in animals and lab studies. Treating it as an established human treatment is not supported by evidence.A comparison is not a recommendation