Retatrutide and GHK-Cu stack claims: what the science says

What did @filmedwithvictoria actually say?

She said she cannot answer whether retatrutide causes hair loss because she is not using it alone. She is stacking it with GHK-Cu (which she calls "GHQ") and attributed her lack of hair shedding and visible baby hair regrowth to that combination. Her exact position: "I don't know the answer to that if you're just on reda maybe, but personally I have not experienced any crazy hair loss shedding." She credits the GHK-Cu for the protective effect.

To her credit, she did not claim retatrutide definitively causes or prevents hair loss. She framed this as personal anecdote, not clinical guidance. That level of epistemic humility is rare on TikTok. But the leap from "I have baby hairs" to "stacking protects you" is where things get shaky.

Does the science back this up?

The short answer: GHK-Cu has real but modest evidence for hair support, while retatrutide's hair loss link is plausible but not yet well-characterized in published data. The stack claim, however, has no clinical evidence behind it at all.

GHK-Cu (copper tripeptide-1) has been studied in the context of hair follicle biology. Uno et al. (1987, Journal of Investigative Dermatology) showed copper peptides could stimulate follicle size in animal models. Pickart et al. (2015, Journal of Aging Science) reviewed GHK's role in tissue remodeling, including hair follicle signaling. These are real findings, but they come from in vitro and animal studies, or small human trials. No large randomized controlled trial has confirmed that GHK-Cu reverses drug-induced hair shedding in humans.

Retatrutide is a triple agonist targeting GLP-1, GIP, and glucagon receptors. Hair shedding (telogen effluvium) is a known side effect class for GLP-1 receptor agonists, likely tied to rapid weight loss causing nutritional stress on hair follicles. Etminan et al. (2024, JAMA Dermatology) found a statistically significant association between GLP-1 agonist use and alopecia reports in a pharmacovigilance analysis. Retatrutide-specific hair data from Phase 2 trials (Jastreboff et al., 2023, NEJM) did not break out hair loss as a primary endpoint.

What did they get wrong (or right)?

She got the uncertainty right. Saying "I don't know" is honest, and the hair loss question for retatrutide specifically is genuinely unresolved in published literature. That is accurate.

What she got wrong, or at least overreached on, is the implied mechanism. Saying "probably because of the GHQ" treats a personal anecdote as a controlled observation. She has no baseline, no control arm, and no way to know whether she would have lost hair on retatrutide alone. It is possible she simply does not have the genetic predisposition that makes GLP-1-associated telogen effluvium likely. Individual variation is a real factor.

The "skin glow" attribution to the stack is similarly unverifiable. GHK-Cu does have collagen synthesis and antioxidant signaling support in the literature (Pickart and Margolina, 2018, Biomedicines), but attributing visible skin changes to a peptide stack based on appearance in a TikTok video is not a meaningful data point.

She also never clarifies what "GHQ" is by its full name. For viewers unfamiliar with peptide shorthand, this creates confusion. Unbranded compound stacks discussed in public health-adjacent content should be named clearly.

What should you actually know?

If you are on a GLP-1 class drug and worried about hair loss, the most likely driver is telogen effluvium from rapid weight loss, not a direct follicle toxicity from the drug itself. Stabilizing weight loss rate, maintaining adequate protein intake, and monitoring micronutrients like zinc, iron, and biotin are approaches with more clinical support than adding a topical or injectable peptide to your stack.

GHK-Cu has a reasonable safety profile and some legitimate science behind it for skin and hair biology. But "I have baby hairs while using both" is not evidence that GHK-Cu blocked retatrutide-related shedding. Correlation in a single user is not causation, and anyone making treatment decisions based on this video should understand that gap clearly.

Retatrutide is not FDA-approved as of mid-2025. Any access is through compounded formulations, which are not equivalent to a brand-name approved product. If you are considering this drug for any reason, that conversation belongs with a licensed provider who can review your full medical history, not a TikTok comment section.