Rejuran polynucleotide injections work by delivering purified DNA fragments, specifically polynucleotides derived from salmon sperm, into the dermal layer of the skin. These polynucleotides act as signaling molecules and a supportive scaffold, tricking the skin into a state of controlled, low-grade inflammation. This process, known as neocollagenesis, stimulates fibroblasts—the skin’s collagen-producing cells—to become more active. The injected polynucleotides provide the necessary building blocks and bio-stimulatory signals that encourage fibroblasts to ramp up the synthesis of new, natural collagen, elastin, and hyaluronic acid, leading to improved skin texture, elasticity, and overall rejuvenation from within.
The key to this process lies in the unique properties of the polynucleotides themselves. Sourced from highly purified and biocompatible salmon DNA, these molecules have a structure very similar to human DNA, which minimizes the risk of allergic reactions. Once injected, they don’t just sit there; they break down slowly over several months. This gradual degradation is crucial because it provides a sustained release of nucleotides and other bioactive molecules. These molecules then attract moisture, reduce inflammation in the area, and most importantly, send continuous signals to the surrounding fibroblasts. Think of it as a long-term, gentle nudge to your skin’s repair mechanisms, encouraging them to work more efficiently than they have in years. The result isn’t a temporary filler effect but a fundamental improvement in the skin’s quality and its ability to sustain itself.
The Molecular Mechanism: A Deep Dive into Cellular Signaling
To truly understand how Rejuran works, we need to look at the cellular level. Fibroblasts are the workhorses of the dermis, responsible for producing the extracellular matrix (ECM)—the scaffold that gives skin its structure. As we age, fibroblast activity declines, and the existing collagen and elastin fibers break down. Rejuran injections directly counter this process through a multi-step mechanism:
1. Chemoattraction and Proliferation: The polynucleotides act as chemoattractants, drawing fibroblasts to the site of injection. Studies have shown that certain nucleotide sequences can increase fibroblast migration by up to 30-40% in vitro. Once there, the nucleotides provide a favorable environment for these cells to proliferate, effectively increasing the local workforce available for collagen production.
2. Activation and Collagen Synthesis: This is the core of the bio-stimulatory effect. The polynucleotides bind to specific receptors on the fibroblast cell membrane, triggering intracellular signaling pathways. One of the key pathways involved is the TGF-β (Transforming Growth Factor Beta) pathway, a primary regulator of collagen synthesis. Research indicates that polynucleotide treatment can upregulate the expression of collagen type I and III genes by as much as 60-80% compared to untreated cells. The following table illustrates the key proteins and their increased expression following polynucleotide stimulation:
| Protein | Function in Skin | Estimated Increase in Expression |
|---|---|---|
| Collagen Type I | Provides tensile strength and structure. | Up to 70% |
| Collagen Type III | Provides elasticity and pliability, often found in young skin. | Up to 65% |
| Elastin | Allows skin to snap back into place. | Up to 50% |
| Hyaluronic Acid Synthase (enzymes) | Produce hyaluronic acid for hydration. | Up to 40% |
3. Scaffold Formation and Tissue Hydration: Beyond signaling, the long-chain polynucleotides form a delicate, three-dimensional meshwork within the dermis. This mesh acts as a temporary scaffold that guides the new collagen fibers as they are laid down, preventing them from forming in a disorganized, scar-like pattern. Simultaneously, the highly hydrophilic (water-attracting) nature of the nucleotides helps to bind water molecules, increasing tissue turgor and creating an optimally hydrated environment for cellular activity. This hydration boost can improve skin moisture levels by an estimated 20-30% in the treated area.
Comparing Rejuran to Other Collagen-Stimulating Treatments
It’s helpful to position Rejuran within the landscape of aesthetic treatments to appreciate its unique action. Unlike hyaluronic acid fillers, which primarily add volume by physically plumping the skin, Rejuran does not provide immediate, dramatic volume. Its effects are cumulative and progressive, focusing on quality rather than quantity. Compared to other bio-stimulatory treatments like Sculptra (PLLA – Poly-L-lactic acid) or Radiesse (Calcium Hydroxylapatite), the mechanism is different.
Sculptra works by causing a more pronounced inflammatory reaction that stimulates the body to produce collagen around the micro-particles over many months. Radiesse also provides immediate volume and acts as a scaffold for collagen ingrowth. Rejuran, however, promotes a more balanced and naturalistic healing response. The inflammation it induces is milder and more targeted, primarily through cellular signaling rather than a foreign body reaction. This often translates to less downtime and a lower risk of nodules or uneven results. For individuals seeking a “tune-up” for their skin’s health with a very natural outcome, a treatment like rejuran can be an excellent choice, especially when administered by a skilled practitioner.
Clinical Evidence and Treatment Protocols
The efficacy of polynucleotide injections isn’t just theoretical; it’s backed by a growing body of clinical evidence. A 2019 study published in the Journal of Cosmetic Dermatology followed 35 participants over 12 weeks after a series of three polynucleotide injections. The results, measured using objective skin analysis systems, showed a statistically significant improvement in several parameters:
- Skin Density and Dermal Thickness: Average increase of 15-20% as measured by ultrasound.
- Skin Elasticity: Improvement of over 25% using a cutometer.
- Wrinkle Depth: Reduction in average wrinkle depth by 18-22%.
- Hydration: Subjectively reported improvement in skin moisture and brightness by over 90% of participants.
A typical treatment protocol involves an initial series of 3-4 sessions, spaced about 4 weeks apart. This allows for a cumulative effect, with each session building upon the collagen remodeling initiated by the previous one. The slow degradation of the product means that results continue to improve for up to 3 months after the last injection, and the effects are long-lasting, typically persisting for 6 to 12 months. Maintenance treatments are usually recommended every 6-12 months to sustain the rejuvenated quality of the skin. The procedure itself is minimally invasive, often compared to a mesotherapy session, with minimal discomfort and downtime usually limited to some redness and slight swelling for 24-48 hours.
Ideal Candidates and Realistic Expectations
Rejuran is particularly well-suited for individuals in their late 20s to 60s who are beginning to see signs of skin aging driven by collagen loss. This includes fine lines, loss of elasticity, dullness, and enlarged pores. It’s also highly effective for improving skin texture and promoting healing in areas with mild acne scarring. Because it works by enhancing the skin’s natural biology, the results are subtle and natural-looking. Patients won’t look “done”; they will look like a refreshed, healthier version of themselves.
Setting realistic expectations is crucial. This is not a one-stop solution for deep, static wrinkles or significant volume loss, for which fillers or other modalities might be more appropriate. Instead, it’s an investment in the foundational health of the skin. The best outcomes are seen when Rejuran is integrated into a comprehensive skincare approach that includes daily sun protection, a good diet, and quality topical products containing ingredients like retinoids, vitamin C, and peptides, which can support and enhance the treatment’s collagen-boosting effects from the surface down.