Background <p>Atrophic acne scars are common. Microneedling (MN) and its combinations can offer effective treatment options.</p> Objective <p>To evaluate the efficacy and safety of microneedling combined with insulin,bFGF or rh-aFGF for atrophic acne scar.</p> Methods <p>A clinical trial enrolled 52 patients divided into MN, MN + insulin, MN + bFGF, and MN + rh-aFGF groups, receiving monthly treatments for 3 sessions. An animal experiment used 40 mice divided into control, MN, and the same combination groups. Clinical outcomes included overall response rate (ORR), ECCA weight score, skin texture score, and adverse reactions. Animal studies assessed dermal thickness, collagen fiber proliferation, and type I/III collagen content.</p> Results <p>Clinically, the MN + bFGF group showed the highest ORR (84.62%), though intergroup differences were not significant. All groups exhibited improved skin texture and ECCA scores (<i>P</i> &lt; 0.05), with MN + bFGF being most significant. No serious adverse events occurred. Histologically significant improvements (dermal thickness, collagen area ratio) were only observed in MN + bFGF (<i>P</i> &lt; 0.05); significant collagen (I and III) improvements were only observed in MN + bFGF and MN + rh-aFGF (<i>P</i> &lt; 0.05).</p> Conclusions <p>MN + bFGF combination therapy indicated statistically superior scar improvement clinically and histologically compared to MN. MN + insulin and MN + rh-aFGF showed potential therapeutic enhancement. No serious adverse events reported. These findings provide help in the treatment of atrophic acne scars.</p> <p><i>Trial registration</i> Parallel controlled trials, ChiCTR2500115176, 2025–12-23, retrospectively registered.</p>