Polynucleotides
4 min readPolynucleotides for Thinning Hair and Scalp Regeneration
Educational reading for licensed practitioners — not clinical or injection guidance.
Polynucleotides made their name in skin quality, but they are increasingly used on the scalp for thinning hair. The logic is consistent with everything the category does elsewhere: rather than forcing a single follicle to behave, polynucleotides aim to improve the environment the follicle lives in. Here is how that translates to hair, what products are used, and what a patient can realistically expect.
The Rationale for the Scalp
Hair health depends heavily on the condition of the scalp — its microcirculation, hydration and the activity of the surrounding cells. Polynucleotides are understood to stimulate fibroblasts, support the formation of small blood vessels (angiogenesis) and exert antioxidant and anti-inflammatory effects. Applied to the scalp, the intended result is a healthier tissue bed: better perfused, less inflamed and more supportive of the follicles it holds.
This is a supportive, regenerative approach, not a follicle transplant and not a guaranteed regrowth treatment. It is best understood as improving the terrain rather than manufacturing new hair.
Where It Fits in a Hair Plan
Thinning hair, particularly androgenetic (pattern) loss, is rarely solved by one modality. Polynucleotides are most sensibly positioned as one component of a broader plan that may include medical therapy, good scalp care and, in some clinics, other injectable approaches. They are frequently discussed alongside PRP and mesotherapy, and can be combined with them.
Realistic candidates are patients with early to moderate thinning and a viable follicle base who understand that this is a course-based, maintenance treatment. Where loss is advanced and follicles are largely gone, expectations must be adjusted accordingly.
The Products Used
Several ranges offer scalp-specific polynucleotide presentations:
- Plinest Hair — the Mastelli scalp presentation, from the range that helped define the category.
- Rejuran — the PDRN-based Korean range, widely used in scalp protocols.
- PolyPhil Hair and PhilArt Hair — Croma's scalp-oriented options.
These are injectable products placed into the scalp; technique, depth and spacing are clinical decisions for the treating practitioner and are not prescribed here.
Course, Aftercare and Expectations
Polynucleotide scalp treatment is delivered as a course, with any benefit developing gradually over the weeks and months that follow rather than immediately. Transient redness, tenderness, small papules or minor bruising at the injection points are commonly reported and usually settle quickly. As with all hair treatments, maintenance sessions are typically needed to sustain any gains, and no specific degree of regrowth can be promised.
A clear compliance note belongs in every patient conversation: no injectable polynucleotide or PDRN product, Rejuran included, holds FDA approval. These are CE-marked and used internationally, and should be described that way rather than as "FDA-approved." The evidence for polynucleotides in hair specifically is still emerging and should be presented honestly, without overstatement.
Combining With Other Treatments
Because polynucleotides work on the terrain rather than directly forcing regrowth, they combine naturally with other approaches. They are often discussed alongside autologous platelet therapy (PRP or PRF), scalp microneedling to assist delivery, and ready-made mesotherapy hair cocktails. Many patients also continue evidence-based medical therapy prescribed by their doctor. The point of combining is to support the follicle from several directions across a course, not to replace a proper diagnosis — which is what determines whether an injectable approach is appropriate at all.
Who Is Not a Candidate
Polynucleotides are not a fit for every case of hair loss. Where the underlying cause is untreated medical or hormonal, or where loss is advanced and follicles are largely absent, expectations must be recalibrated and other routes considered. Standard injectable exclusions apply: active scalp infection or inflammation, bleeding disorders, pregnancy and lactation, and relevant allergy history, including fish allergy given the source material. A proper assessment before starting is essential rather than optional.
The Takeaway
Polynucleotides offer a regenerative, environment-first approach to thinning hair: supporting scalp health and the follicular bed rather than promising dramatic regrowth. Used as part of a wider, realistic plan — and described accurately as a CE-marked, not FDA-approved, course-based treatment — they are a reasonable option for the right candidate.
Explore scalp-specific options in the hair growth range.