Rejuran Side Effects

Rejuran side effects are typically mild and temporary, but it is important to know which reactions are normal and how the recovery process works. Many people seek information about Rejuran side effects before considering a treatment, as safety, downtime, and potential risks play a significant role when choosing a clinic.

Rejuran is a polynucleotide treatment designed to support skin regeneration, collagen stimulation, and overall skin quality. Because it is not a traditional dermal filler, the recovery phase often looks different from volumising treatments. On this page, you can find out which side effects may occur, how long they usually last, when to contact a medical practitioner, and what to expect during recovery. This allows you to make an informed decision when comparing clinics and treatment options.

Is a Rejuran treatment safe for your face?

Yes, a Rejuran treatment is considered medically safe when carried out by a qualified practitioner. The active ingredient consists of highly purified polynucleotides (PN) extracted from salmon DNA. Because this material is biologically very similar to human DNA, it is highly biocompatible. This means the fluid is usually recognised by the skin cells without causing a prolonged foreign body reaction or chronic inflammation.

Additionally, the product holds European CE certification for intradermal injections. However, the safety of any injectable treatment depends heavily on the skill and expertise of the practitioner, as well as strict adherence to hygiene protocols. An injectable treatment is highly personal; always seek advice from a qualified aesthetic practitioner who can properly assess your skin condition.

Medical contraindications

Although the product is generally well-tolerated, the treatment should not be carried out if certain medical contraindications apply. A responsible practitioner will refuse or postpone the treatment in cases of:

• Pregnancy and breastfeeding (due to a lack of clinical safety data for this group).

• Active autoimmune diseases or conditions that disrupt the immune system.

• Acute skin infections, cold sores (herpes labialis), or open wounds in the treatment area.

• A known, severe allergy to fish, shellfish, or salmon proteins.

Rejuran side effects: What is a normal skin reaction?

To avoid unnecessary worry after your treatment, it helps to distinguish between mild, expected reactions to the injections and actual medical complications. Localised reactions almost always occur immediately after the session. This is part of the natural healing process and indicates that the skin has been stimulated.

Symptom vs. Risk Table

Why do temporary papules (bumps) appear?

Almost every patient will leave the clinic with dozens of small, visible bumps on their face. This is an unavoidable result of the specific injection technique used for polynucleotides.

Because the fluid must be placed superficially in the dermis to reach the fibroblasts effectively, these small papules form. Since Rejuran has a relatively high viscosity, it takes time for the surrounding tissue to fully absorb the liquid. The appearance of these bumps does not mean the treatment has failed; rather, it shows that the product was placed at the correct anatomical depth.

What is the recovery time for a Rejuran treatment?

The standard recovery time for Rejuran treatment is between 24 and 48 hours. Because the fluid is injected superficially, the healing process typically follows a set pattern:

• Hours 1 - 12 (Acute phase): Distinct, small bumps (papules) appear at the injection sites. Mild redness (erythema) and local warmth are entirely normal.

• Hour 24 (Absorption phase): The papules usually reduce in volume by 50% to 80% as the polynucleotides are absorbed by the surrounding tissue.

• Days 2 - 3 (Recovery phase): For most people, the skin surface is largely flat again. Any minor bruising may still be visible but can be concealed with mineral makeup from this point onwards.

If the treatment was performed in the delicate area around the eyes, localised swelling may sometimes last slightly longer due to the specific anatomy of the tear trough. You can find more details on our dedicated page about Rejuran under the eyes, or view the complete daily schedule on the Rejuran recovery page.

Risks of rare complications and fish allergies

Although the purification process for the salmon DNA is rigorous, the biological source of the product must be considered. People with a known, severe anaphylactic allergy to fish or shellfish have a higher risk of an allergic reaction to polynucleotides. While mild sensitivities rarely cause issues, a severe fish allergy is an absolute contraindication.

Furthermore, any treatment that breaks the skin barrier with needles carries a minimal risk of bacterial infection. This risk can be significantly reduced by carefully following all aftercare instructions and ensuring you only visit a practitioner working in a sterile, clinical environment.

Safety profile: Rejuran vs hyaluronic acid fillers

It is a common misconception that Rejuran carries the exact same risks as traditional hyaluronic acid fillers. When looking at the general safety profile, these two product categories are fundamentally different. Because Rejuran is a liquid biostimulator and does not add mechanical volume to the face, the most severe filler-related complications are highly unlikely.

Safety Profile Comparison

During a standard filler treatment, placing the gel too superficially can lead to a bluish discolouration under the skin (the Tyndall effect) or, in the worst-case scenario, a blocked blood vessel (vascular occlusion). Because polynucleotides are liquid and do not contain cross-linking agents (chemicals used to maintain volume), the product cannot easily compress or block blood vessels in the same way. See the full analysis regarding the mechanical differences between these products on our Rejuran or fillers page.

Crucial aftercare instructions to minimise side effects

Strictly following your practitioner's aftercare rules is essential to minimise the risk of prolonged redness, unwanted swelling, or infection. The first 48 hours largely determine the speed of your recovery:

• Skin hygiene (First 6 hours): Do not touch the treated area with unwashed hands. The microscopic injection points remain open and are susceptible to bacteria.

• Cosmetics and SPF (First 24 hours): Do not apply regular makeup, stimulating skincare (such as retinol or active vitamin C), or sunscreen. Allow the skin to breathe to help the papules absorb quickly.

• Sleeping position: Change your pillowcase to a clean one on the evening of your treatment, and try to sleep on your back to prevent friction.

• Heat sources and exercise (First 48 hours): Avoid saunas, steam rooms, hot showers, and strenuous exercise. Excessive sweating and increased blood pressure can worsen redness and swelling.

• UV protection: Avoid direct exposure to strong sunlight or sunbeds while the skin still shows redness or bumps, to help prevent post-inflammatory hyperpigmentation (PIH).

Comparing clinics for safety

Would you like to know which qualified medical practitioners in your area have experience with Rejuran? Use our independent platform to compare Rejuran clinics, check their qualifications, and review their safety standards.

Frequently asked questions about Rejuran side effects