Facial hollowing after weight loss: what is happening?

Why does the face become hollow?

Under the skin of the face, fat is arranged in compartments, some superficial, others deep. They are what give the cheeks, the temples and the area under the eyes their fullness. When you lose a lot of weight, these compartments shrink too.

The skin, which rested on this volume, loses part of its support. Recent medical reviews mainly describe:

• hollower cheeks, in the middle of the face and below the cheekbones;
• hollow temples;
• a deeper hollow under the eyes;
• more visible folds, for example between the nose and the mouth;
• skin that looks looser, on the face as well as the neck.

A team in the United States measured this on CT and MRI scans taken before and after treatment in 20 people, with a median age of 54, who had lost 11 kg on average. The volume of the midface had decreased by a median of 9%, more in the superficial fat than in the deep fat.

Is it an effect of the medicine?

The media have given this phenomenon a nickname based on a brand name, which suggests an effect specific to the medicine. Two literature reviews published in 2026 conclude otherwise: similar changes are described after obesity surgery or after other substantial weight loss. What matters most is the amount of weight lost, on top of each person's age and anatomy. An international expert panel has in fact recommended replacing this nickname with neutral terms.

What about speed? Experienced practitioners observe more marked changes when weight loss is both large and rapid. But the specific effect of speed has not yet been measured: it is plausible, not proven.

Is everyone affected?

No. In a survey of 1,226 people treated with medication for weight loss, 29% reported a loss of facial volume, more often beyond 20% of weight lost. So the majority did not report it. These are self-reported impressions, not measurements; experts also stress that this accelerated ageing is not inevitable.

Age and skin quality play a role. Over the years, the skin contains less collagen and fewer elastic fibres, and the face has often already lost volume: weight loss accentuates what was there. After obesity surgery, in 65 people, surgeons estimating their age judged them on average almost three years older than before the operation, although only one year had passed. The gap was clearer in men over 40 and after the largest weight losses.

Can these changes be limited?

No method has been shown to protect the face specifically. The recommendations published to accompany these treatments aim first to preserve muscle and health:

• enough protein, to be adjusted with the doctor or dietitian who follows you;
• regular muscle-strengthening physical activity;
• preventing nutritional deficiencies, since appetite is reduced;
• a pace of treatment and weight loss decided with the prescribing doctor, according to your needs.

Obesity treatment brings important health benefits, and its benefit-risk balance is a matter for the doctor who prescribes it. If your face concerns you, talk to the doctor who follows you, and do not change anything on your own.

When should a treatment be considered?

As long as weight is falling, the face keeps changing. Volume restored too early may become insufficient a few months later. Experts are divided: some suggest acting early, others waiting for a stable weight for a more predictable result. No study has yet compared these two approaches.

For my part, I generally wait until your weight has stabilised. At the consultation, I ask which treatment you are on, I examine you and I analyse your face on standardised photographs with the ZenFace method. Photos from before your weight loss can also help to understand what has changed.

What hyaluronic acid can do, and its limits

Hyaluronic acid can restore support where fat has melted away: temples, cheekbones, sometimes the hollow under the eyes. The aim is not to "fill" the face but to give it back some support, in moderate amounts. According to experts, many people indeed fear looking as if they have regained weight after a treatment. I describe the technique in the article on cheekbones.

Its limits are clear:

• It does not tighten very loose skin. Compensating with a lot of volume could make the face look heavy. When laxity predominates, surgery may be more suitable: we discuss it together.
• The evidence remains thin. A 2026 systematic review found only four studies, without a comparison group, totalling 98 treated people. So the different treatments cannot yet be compared for effectiveness in this situation.
• If weight keeps falling, the result may fade faster and require further sessions.
• The usual contraindications apply, such as pregnancy, breastfeeding or a skin infection in the area to be treated.

The check-up around day 15 makes it possible to assess the result once the swelling has gone. Hyaluronidase, which dissolves the gel, is always available at the practice.

What I do not do

The reviews also describe so-called biostimulator products, radiofrequency or ultrasound devices, fat grafting and surgical facelifts. I do not perform any of these treatments. Nor do I give an opinion on your obesity treatment: that is a matter for the doctor who prescribes it.