What should I put on my scalp after PRP injections?

Use a 100% pure mulberry silk pillowcase the night after PRP or PRF scalp injections. During the 4-8 hour post-injection window, cotton's hygroscopic properties actively draw moisture from the scalp surface, removing the superficial fraction of the injected growth factor concentrate before it can be fully absorbed by follicular stem cells. Silk is hydrophobic — it retains zero biological fluid. Every PDGF and VEGF molecule stays where it was injected.

PRP / PRF Hair Treatment

PRP & PRF Scalp Injections: Why Cotton Absorbs the Growth Factors You Just Paid For

Protect my PRP →

Platelet-Rich Plasma (PRP) and Platelet-Rich Fibrin (PRF) injections for hair loss represent a €200 to €600 per-session investment in concentrated autologous growth factors — PDGF, VEGF, EGF, TGF-β — injected directly into the scalp dermis to stimulate dormant follicles and extend the anagen growth phase. The biological rationale is sound. The clinical outcome, however, depends on a factor that most clinics never mention: what happens to the scalp in the hours immediately following injection, while the growth factor gradient is at its peak concentration in the dermis and the injection sites are still microscopically open.

The Absorption Window: 4 to 8 Hours of Peak Growth Factor Availability

PRP and PRF work by creating a sustained-release depot of growth factors in the scalp dermis. Immediately post-injection, the injected platelet concentrate has not yet formed a stable fibrin matrix — it is in a liquid or semi-liquid state, and the injection micro-channels remain temporarily patent. During this window — typically 4 to 8 hours post-injection — any hygroscopic surface in contact with the scalp will draw moisture and, with it, the superficial fraction of the injected growth factor concentrate. Cotton's hygroscopic coefficient is among the highest of any natural fiber: it actively draws moisture from any surface it contacts. A cotton pillowcase against a freshly PRP-treated scalp is not a neutral surface. It is an active drain on the treatment's biological payload.

        "Silk is hydrophobic: its surface energy prevents any adhesion of aqueous biological fluids, including the growth factor-rich exudate from fresh PRP injection sites. Every PDGF and VEGF molecule that would be drawn into a cotton fiber instead remains in the scalp dermis, available to the follicular stem cells it was injected to activate. The difference between cotton and silk on a PRP night is the difference between a full dose and a partial dose."
      

Silkhouse silk pillowcase for PRP PRF scalp injection recovery

Mechanical Trauma to Injection Sites: The Friction Risk on a Sensitized Scalp

PRP and PRF injections leave the scalp in a state of acute micro-trauma: dozens of needle punctures across the treatment zone, each representing a temporary breach in the epidermal barrier. The scalp is often sensitive and slightly swollen post-treatment. Cotton's rough fiber surface generates friction against these micro-puncture sites during sleep, mechanically stimulating already-sensitized tissue and triggering a secondary inflammatory response that competes with — and dilutes — the targeted growth factor signaling the treatment is designed to produce. Silk's protein surface generates zero friction against injection sites: no secondary inflammation, no mechanical disruption of the platelet matrix forming at each injection point.