Polynucleotides (PN) Injections: The Skin Booster Trend Explained

Polynucleotide (PN) injections are a type of skin booster that uses purified DNA fragments, usually from salmon or trout, to support the skin's natural repair processes. They are injected into the skin to improve texture, hydration, fine lines and overall skin quality, rather than to add volume like a filler. The trend has grown quickly because PN treatments aim for a subtle, "better skin" result with relatively short downtime. The evidence is encouraging but still developing, and results are gradual and moderate rather than dramatic.

This article explains what polynucleotides are, why they have become popular, what they can and cannot do, and how to think about them alongside other skin treatments.

What Polynucleotides Are

Polynucleotides are long chains of nucleotides, the basic units that make up DNA. For cosmetic and medical use, they are extracted from fish reproductive cells, most commonly salmon, and then highly purified. Purification removes proteins and other materials so that the product is considered biologically compatible and low in allergy risk.

PN is not new to medicine. Polynucleotides have been used in areas such as wound healing, joint injections and eye care in some countries for years before becoming popular in aesthetics. In skin treatments, PN products are available under various brand names. In Korea, Rejuran is the best known, but there are other PN-based products both in Korea and internationally.

Why the Trend Has Taken Off

Several factors explain the growing interest in PN injections:

• Focus on skin quality: many people want healthier-looking skin rather than changes to their face shape. PN targets texture, glow and resilience.
• Natural-looking results: because PN does not add volume, the results tend to look subtle.
• Versatility: PN can be used on the face, under the eyes, on the neck and on acne scars, depending on the product.
• Korean skincare influence: the "glass skin" ideal and the popularity of Korean skin clinics have brought skin boosters to international attention.
• Combination potential: PN is often used alongside lasers or other procedures to support recovery.

How PN Injections Are Thought to Work

The exact mechanisms are still being studied, but research suggests polynucleotides may:

• Support fibroblasts, the cells responsible for producing collagen and elastin
• Have anti-inflammatory and soothing effects on stressed or irritated skin
• Bind water to improve hydration and plumpness
• Help the skin recover after damage, such as from sun exposure or other procedures

Clinical studies have reported improvements in elasticity, hydration, fine wrinkles and scar appearance. However, many studies are small, run over short periods or are sponsored by manufacturers. Larger, independent long-term research is still limited. It is reasonable to view PN as promising and generally well tolerated, while being cautious about bold marketing claims.

What PN Can and Cannot Do

Setting realistic expectations helps avoid disappointment. PN injections may help with:

• Dull, dehydrated or tired-looking skin
• Fine lines and crepey texture, including around the eyes and neck
• Rough texture and enlarged-looking pores
• Shallow acne scars, especially combined with other treatments
• Sensitive or damaged skin that needs support

PN injections are not designed to:

• Restore significant lost volume or reshape features
• Lift sagging jowls or loose skin
• Remove deep wrinkles or strong expression lines
• Treat pigmentation such as melasma on their own

For those concerns, filler, collagen stimulators, lifting devices, lasers or muscle-relaxing injections may be more appropriate, sometimes combined with PN.

What to Expect From Treatment

PN is usually injected into the upper layers of the skin using many small injections, either by hand or with an injector device. Numbing cream is commonly applied first. The process generally takes under an hour including numbing.

Afterwards, small raised bumps at injection points are common and usually settle within one to a few days. Redness, mild swelling and small bruises may occur. Most people return to normal activities quickly, though they may want to avoid social events for a day or two.

Treatment is usually given as a course, often several sessions a few weeks apart, followed by maintenance if desired. Results tend to build gradually over weeks.

Safety and Who Should Be Cautious

PN injections are generally considered to have a good safety profile when performed by a trained practitioner using genuine products. Still, they are medical procedures with possible risks, including infection, persistent lumps and allergic reactions. You should discuss treatment carefully, or it may be postponed or avoided, if you:

• Have a fish or salmon allergy
• Are pregnant or breastfeeding
• Have an active skin infection, cold sore or inflamed acne in the area
• Have an autoimmune condition or take medicines that affect healing or bleeding

Because PN products have grown in popularity, counterfeit or unregulated products can be a concern in some markets. Ask which product is being used and make sure it comes from a reliable source.

PN Compared With Other Skin Boosters

PN sits among several injectable skin boosters. Hyaluronic acid skin boosters focus mainly on hydration. PDRN, another salmon-derived ingredient, consists of shorter DNA fragments and is often used for a lighter, regenerative effect. Collagen stimulators such as poly-L-lactic acid or PLA-based products work more on structure over months. Your doctor may recommend one, or a combination, depending on your skin.

Frequently asked questions

Are PN injections the same as Rejuran?

Rejuran is one brand of PN injection. Other brands exist, and formulations differ in concentration and added ingredients.

How soon will I see results?

Some people notice better hydration within a couple of weeks, but changes in texture and elasticity usually take several sessions.

Are PN injections suitable for men?

Yes. Skin quality concerns affect people of all genders, and PN can be used for both men and women.

Can I have PN injections if I already have filler?

Often, yes, but tell your doctor about any previous fillers or treatments so they can plan placement and timing safely.

Talk to a Qualified Dermatologist

Polynucleotides are an interesting and increasingly popular option for improving skin quality, but they are not right for every concern. A qualified dermatologist can assess your skin, explain realistic results, and help you decide whether PN injections, another treatment or a combination best suits you.