Non-Surgical Buttock Remodelling: What One Protocol Reported

A 2023 case series from Brazil described six women who had their buttock contour treated in one session that combined hyaluronic acid filler with poly-L-lactic acid (PLLA), a collagen stimulator. At 90 days the authors reported modest increases in measured projection and circumference and no complications. With six patients, no comparison group and short follow-up, this is early research that cannot tell us how safe or lasting the approach is.

Why this was studied

Interest in changing buttock shape without surgery has grown, but some non-surgical approaches have caused serious harm, particularly when large volumes or unregulated substances are injected, or when injections are given by untrained people. The authors wanted to describe a more conservative protocol using smaller amounts of hyaluronic acid for shape and PLLA for gradual skin and tissue support, placed in a defined layer under the skin.

What the researchers did

Six women aged 23 to 43, all with a healthy body weight, were treated at a private clinic. People with higher body weight, autoimmune disease, a tendency to keloid scars, pregnancy or breastfeeding, bleeding disorders or blood-thinning medication were excluded.

The clinicians marked zones for lifting, widening and projection. They placed PLLA across the upper and lower parts of both buttocks and a hyaluronic acid filler in the upper part, using a long blunt cannula in the deep layer of fat under the skin, above the muscle. Results were checked with photographs, circumference measurement, ultrasound and an improvement scale rated by the patients, the injector and an independent evaluator, at 45 and 90 days.

What they found

On ultrasound with the patient standing, the depth of tissue at the centre of the buttock increased by an average of about 17 mm. Circumference increased by an average of about 1.6 cm overall, with the largest change at the upper buttock. Every patient showed some gain, and none were rated as unchanged or worse.

Ultrasound did not show lumps, granulomas or movement of the filler away from where it was placed, and no complications were reported during the 90 days of follow-up.

How strong is this evidence?

This is a small case series. It shows what happened to six carefully selected women over three months, but it cannot establish safety or effectiveness more broadly. Specifically:

• Six patients is far too few to detect uncommon or rare complications.
• There was no control group, and no statistical testing was presented.
• Follow-up ended at 90 days, before the full PLLA effect and before delayed reactions might appear.
• The amount of hyaluronic acid used was not clearly reported, and some tables in the paper do not match each other.
• Improvement ratings are partly subjective.

The authors described a good balance of results and safety, but six uncontrolled cases cannot support a strong claim either way. It is also worth noting that the protocol used particular commercial products available in Brazil, so the findings may not apply to other products. Measurements were taken with the patient standing and lying down, and the change in projection appeared only in the standing position, which shows how much posture and measurement method can influence reported results.

What it means for you

Buttock injections for shape are an area of ongoing research. Product authorization for body use, including whether a given product is approved by Health Canada for the buttocks, varies, and many uses are off-label. This article describes a study only and does not describe a treatment offered by HealthPark.

The most important safety message is this: never have buttock injections from unregulated sources, at home, in non-medical settings, or with substances such as liquid silicone or unknown "fillers". These have caused severe infections, disfigurement and deaths. Injections placed too deep, into or under the gluteal muscle, can reach large blood vessels and carry a risk of life-threatening embolism. The protocol in this study deliberately stayed in the layer above the muscle and used ultrasound to check for large vessels.

Even when done carefully, risks include bruising, swelling, pain, lumps, asymmetry, infection, delayed inflammatory reactions and filler movement. Results are temporary and may need repeated treatment. Those who should not consider it include people who are pregnant or breastfeeding, have active infection, autoimmune disease, keloid tendency or bleeding disorders. Do not stop blood thinners on your own.

For many people, strength training, weight stability and accepting natural body shape are reasonable choices. Where skin laxity or contour changes are significant, a surgical opinion may be more appropriate. Our body contouring overview and article on who is a good candidate for body contouring explain established options.

Questions to ask at your consultation

• What evidence supports injections in this body area, and how long has it been studied?
• Which product would be used, and is it authorized in Canada for this use?
• How deep will injections be placed, and how do you avoid large blood vessels?
• What would happen if a complication developed weeks or months later?
• Is a non-injection option or a surgical referral more suitable for me?

Frequently asked questions

Is this the same as a surgical buttock lift or fat transfer?

No. This protocol used injectable products in modest amounts and produced changes measured in millimetres to a couple of centimetres. It is not comparable in scale to surgery and carries its own different set of risks.

Why combine hyaluronic acid with PLLA?

The authors used hyaluronic acid for some immediate shape and PLLA for gradual collagen support. Whether combining them works better than either alone was not tested in this study.

Are the results permanent?

No. Both products are absorbed over time. This study did not follow patients long enough to say how long changes last.

If you are thinking about body contour, HealthPark Medical Aesthetics can discuss what is realistic, which options have stronger evidence, and when another specialist would be a better fit.

Source

Faria G, Boggio R, Bellini M. Glutaeal remodelling protocol: volumization with hyaluronic acid and collagen biostimulation with poly-L-lactic acid. Skin Health and Disease, 2023. Read the study