Do growth hormone peptides actually raise GH, or is that just marketing?

Some do raise growth hormone in humans. In short randomized studies, long-acting CJC-1295 increased measured GH and IGF-1 after administration. A separate human infusion study of ipamorelin recorded a pulse of GH release. Those are measured pharmacological effects, not merely testimonials. CJC-1295 acts through the growth-hormone-releasing-hormone pathway, while ipamorelin is a GH secretagogue acting through the ghrelin receptor pathway.[1][2][3]

The important limit is what those studies measured. A rise in GH or IGF-1 does not by itself demonstrate greater strength, faster injury recovery, better sleep, or a longer life. The ipamorelin study used intravenous infusion in healthy men, which is not interchangeable with claims about chronic subcutaneous combination products. Small, short studies also cannot settle long-term safety.[1][2]

Names matter here: the long-acting CJC-1295 studied in the clinical trial used an albumin-binding modification commonly called DAC. Products marketed as “CJC-1295 without DAC” should not inherit its duration-of-action findings. The defensible conclusion is that hormone stimulation is real for studied compounds, while many performance and anti-aging claims go beyond the outcomes those trials actually tested.[1]