Polynucleotides are injectable products based on fractions of DNA derived from salmon trout. There is emerging data questioning how widely they are now being used in aesthetics and urging caution - topical (skin) application is one thing, injecting is another. There is a lot of hype and excitement and focus on these treatments but as is often the case in aesthetics the science is playing catch-up.

They work by stimulating fibroblasts through A2A receptors in part, though their full mechanisms of action are still being studied.

Of late there has been some concern expressed about how widely they are being used in aesthetics and whether we have the robust data to back up this new application.

As with all products, there are 'cheap' imitations and low grade products, and these may be associated with unreliable results and effects; highest pharmaceutical quality products should only ever be injected but this isn't always the case.

Treatment is injection-based and there can often be a stinging discomfort during injections, but this is not always the case.

Serious side effects have not been reported with high quality products.

The side effects are therefore those associated with any injection - bruising, swelling, redness and discomfort at the injection site with the potential (very uncommon) for infection.

Low quality products are in use widely and side effects are being reported.

There is concern that polynucleotides may be pro-inflammatory and inflammation is a key driver of skin ageing.

There may be some small blebs/lumps at the sites of injection, these usually settle quickly but can take longer in some patients.

A second treatment is usually advised at around 3-4 weeks.