Rejuran is a specialized type of polynucleotide (PN) injectable treatment derived from purified salmon DNA, designed to stimulate the skin’s natural healing and regenerative processes to combat signs of aging. It works by delivering these polynucleotides into the dermal layer of the skin, where they act as signaling molecules to promote collagen production, improve skin elasticity, enhance hydration, and repair damaged tissue from within. Unlike traditional fillers that primarily add volume, Rejuran focuses on cellular-level rejuvenation, making it a regenerative treatment that addresses the underlying causes of skin aging.
The core mechanism hinges on the biological activity of polynucleotides. These are long-chain molecules composed of nucleotides, the fundamental building blocks of DNA and RNA. When injected into the skin, they don’t integrate with human DNA but instead function as bio-stimulatory messengers. They are recognized by fibroblasts—the skin’s collagen-producing cells—which are then prompted to become more active. A 2020 study published in the Journal of Cosmetic Dermatology found that PN injections led to a statistically significant increase in collagen density of up to 28% over a 12-week period compared to baseline measurements. This process effectively thickens the dermis, the skin’s supportive layer, which naturally thins with age.
Beyond collagen induction, Rejuran excels at improving skin quality through intense hydration. The polynucleotide chains are highly hydrophilic, meaning they have a strong ability to bind water molecules. A single molecule can hold up to 1,000 times its weight in water. This action creates a deeply hydrated environment within the skin, plumping up fine lines and giving the complexion a dewy, revitalized appearance. This is a key differentiator from hyaluronic acid (HA) fillers; while HA also hydrates, it is eventually broken down by the enzyme hyaluronidase. Polynucleotides are not susceptible to this enzyme, potentially leading to longer-lasting improvements in skin hydration and texture.
The repairative properties of Rejuran are another critical facet. The polynucleotides have been shown to reduce inflammation and support tissue repair. They do this by modulating cellular activity and promoting angiogenesis—the formation of new, tiny blood vessels. This improved microcirculation enhances nutrient and oxygen delivery to skin cells, accelerating recovery from photodamage (sun damage) and creating an overall healthier skin environment. This makes it particularly beneficial for individuals with skin that appears tired, dull, or has been damaged by prolonged sun exposure.
The treatment protocol for Rejuran typically involves a series of 3 to 4 sessions, spaced about 4 weeks apart, to achieve optimal and cumulative results. A single session is often insufficient because the regenerative process is gradual. The following table outlines a typical treatment journey and the expected improvements at each stage.
| Session Number | Timeline (Weeks) | Primary Focus & Observed Effects |
|---|---|---|
| 1 | 0-4 | Initial Hydration & Micro-Repair: The skin begins to feel more supple and looks brighter. Fine lines may appear softened as the deep hydration takes effect. |
| 2 | 4-8 | Enhanced Elasticity & Texture Refinement: Collagen stimulation becomes more evident. Skin feels firmer, and pores may appear less visible due to improved skin density. |
| 3 | 8-12 | Consolidation of Results & Structural Improvement: The cumulative effect of collagen remodeling is visible. There is a noticeable reduction in the depth of wrinkles and an overall improvement in skin tightness and resilience. |
| Maintenance | Every 6-12 Months | Long-Term Sustenance: After the initial series, maintenance sessions are recommended to prolong the regenerative benefits and counteract ongoing aging processes. |
When comparing Rejuran to other popular anti-aging treatments, its unique position becomes clear. It is not a direct replacement for botulinum toxin (e.g., Botox) or traditional fillers but rather a complementary therapy. Botox works by relaxing muscles to smooth dynamic wrinkles (like frown lines), while fillers like those based on hyaluronic acid are used to restore lost volume in areas like the cheeks and lips. Rejuran, on the other hand, works holistically to improve the overall health and quality of the skin. Many practitioners now advocate for combination therapies, using Rejuran as a foundational treatment to enhance the skin’s “canvas” before applying more targeted treatments like fillers. For a deeper dive into how these treatments compare, a great resource is Rejuran.
The safety profile of Rejuran is generally considered excellent because the polynucleotides are highly purified and biocompatible. Since they are derived from salmon DNA, the primary concern is a potential allergic reaction in individuals with a known fish allergy. However, the manufacturing process involves rigorous purification to remove proteins and impurities, making severe allergic reactions rare. Common side effects are similar to other injectables: mild redness, swelling, bruising, or tenderness at the injection sites, which typically resolve within 24 to 48 hours. The risk of lumps or irregularities is lower than with some thicker fillers because Rejuran is injected more superficially using techniques like micro-droplets or linear threading.
Clinical data supports its efficacy. In a Korean study involving 52 participants with moderate facial aging, researchers used objective measures like the Cutometer® (a device that assesses skin elasticity) and subjective physician/patient assessments. After a full treatment cycle, over 90% of participants showed measurable improvement in skin elasticity and hydration. Patient-reported satisfaction scores were consistently high, particularly regarding improvements in skin brightness, smoothness, and the reduction of fine wrinkles. The results are not as immediately dramatic as with a filler, but they develop over weeks, leading to a more natural-looking rejuvenation that doesn’t alter facial contours abruptly.
The ideal candidate for Rejuran is someone who is beginning to see the early signs of aging, such as loss of elasticity, fine lines, and dullness, or someone with skin that has been damaged by environmental factors. It is also an excellent option for those seeking “prejuvenation”—preventative treatments to maintain skin health and delay more significant signs of aging. It is less suitable for individuals seeking to correct severe volume loss or deep, static wrinkles, where a combination approach with a filler would be more appropriate. The treatment is versatile and can be used on various areas, including the entire face, neck, décolletage, and even the back of the hands.
From a biochemical perspective, the purity and molecular weight of the polynucleotides are critical to their function. High-quality Rejuran products contain polynucleotides with a specific molecular weight range (typically between 500 and 1,500 kilodaltons) that optimizes their bioavailability and bioactivity. This ensures the molecules are large enough to persist in the skin and exert their effects but small enough to be effectively administered through fine needles. The manufacturing standards, often adhering to strict pharmaceutical-grade protocols, are what differentiate a reliable PN product from others on the market.