Ozempic face and Mounjaro face: why the face goes first, and what actually works
We prescribe weight-loss injections at Sebastian-Rose. We also treat faces. So we see the same thing from both sides of the desk: a patient who has done brilliantly on Mounjaro or Wegovy, is two or three stone lighter, feels better than they have in years, and hates what it has done to their face.
The cheeks have flattened. The jawline that used to be a line is now a soft curve with the beginnings of jowls either side of the chin. The skin along the jaw feels loose rather than thin. People call it "Ozempic face" online, which is unfair on the drug, because it is not the medication doing it. It is the speed of the fat loss, and it would happen with any method that took the weight off that fast.
Until recently, the honest answer to this was a compromise. A hyaluronic acid filler puts the volume back on the day, but it does nothing about the laxity, and on a face that has lost its fat pads it can look like a patch. A collagen stimulator such as Sculptra rebuilds the support, but over months and over a course, with nothing to show at the first appointment. HArmonyCa is the first product that does both in a single syringe, and the evidence behind it now includes a study on exactly the kind of face we are describing. That is why we have added it to the clinic.
Why weight-loss injections change the face
GLP-1 medications such as semaglutide (Wegovy, Ozempic) and tirzepatide (Mounjaro) work by reducing appetite and slowing gastric emptying. The weight comes off from everywhere, and the face has no way to protect its own fat. The deep and superficial fat pads of the cheeks, the pre-jowl area and the temples shrink along with everything else.
Two things then happen at once. The skin has less underneath it to sit on, so it drops, and the drop shows first along the jawline because that is where gravity and loose skin meet. Second, the skin itself is not what it was. Weight loss at that speed reduces fibroblast activity, and fibroblasts are the cells that make collagen, elastin and your own hyaluronic acid. One UK dermatologist has described routinely starting collagen-stimulating treatment during a patient's weight loss for that reason: to scaffold the face before the support goes, rather than rebuild it afterwards.
So the problem is two problems. Volume that has gone, and a skin envelope that has lost its spring. A treatment that only addresses one will only half work.
What HArmonyCa is, and why it fits this problem
HArmonyCa is made by Allergan Aesthetics, the company behind Juvéderm and Botox. Each syringe contains a cross-linked hyaluronic acid gel at 20 mg/ml with microspheres of calcium hydroxylapatite, the same collagen-stimulating mineral used in Radiesse, making up just over half its weight. The version we use contains lidocaine for comfort. It is CE-marked, injected with a cannula into the deeper tissue of the cheeks and jawline, and it is doing two jobs at once.
The hyaluronic acid replaces the volume on the day, so the cheek is supported and the jawline is defined before you leave the clinic. The calcium hydroxylapatite then sits in the tissue as a scaffold, and over the following weeks your own fibroblasts, the cells that weight loss has been suppressing, lay down new collagen around it. As the gel is absorbed, the collagen takes over the lifting. For a face that has lost both its fat and its spring, that is the right shape of treatment.
What the evidence actually shows
This is not a launch-day product. It has been used across Europe since 2021, and the data has caught up with it. The study that matters most was published in the Journal of Cosmetic Dermatology in September 2025: 140 patients across two French clinics with moderate to severe mid-face volume loss, treated once in the cheeks and jawline and followed for a year. It is the same clinical picture as a face after rapid weight loss.
At one month, 82.8% of patients had improved by at least one grade on Allergan's volume deficit scale. Investigators rated 98.5% as improved or much improved, and patients rated themselves that way 91.8% of the time. The effect peaked between months three and six, which is when the collagen has formed, and at twelve months 65.9% were still improved on the volume scale and 72.6% still rated themselves improved. That pattern, a good result on day one that gets better before it slowly settles, is the hybrid working as designed.
The part we find most persuasive is the measurement. The researchers used markerless 3D tracking of the skin surface and found it had moved outward and upward, the signature of tightening and lift rather than just filling, with the change sustained through the full year. A separate Italian study of 129 patients in 2024 followed people for nine months and found the improvement held during facial movement, not just at rest; the authors called it a dynamic filler for that reason.
Two details from the 2025 study matter for our patients specifically. First, results were consistent across age, sex, skin type and injection volume, and men responded at least as well as women (93.8% at one month). The median patient in the study was 59, so this is not a treatment for the thirties only. Second, the researchers were candid about side effects, and so will we be. Nearly everyone had tenderness, pain or firmness at the injection sites, most of it mild and gone within two weeks. Injection-site pain was reported as treatment-related in 11.4% of patients, a lump or firm area in 10.7%, and headache in 7.1%. A small number of lumps were still present at twelve months. There were no serious treatment-related events. We manage this by cannula placement, conservative volumes, review of everyone at two to four weeks, and honesty at consultation about the fact that the collagen component cannot be dissolved.
More is coming. Allergan is running a 252-patient trial comparing HArmonyCa directly against a conventional hyaluronic acid filler, due to complete in late 2026. When it publishes we will write it up here, whichever way it falls.
Where HArmonyCa sits against what we already offer
We did not add HArmonyCa because it is new. We added it because it fills a gap between three treatments we already use, and the gap is exactly where the weight-loss face lands.
A hyaluronic acid filler is still the right choice when the problem is purely volume and the skin is good: lips, a targeted cheekbone, a chin that needs projection. It is fully reversible with hyaluronidase, which HArmonyCa is not once the collagen has formed.
Sculptra is still the right choice for diffuse, whole-face loss across the temples, cheeks and jaw, where you want collagen everywhere and can wait for it. It is a course, and the result builds over months.
Radiesse shares HArmonyCa's calcium hydroxylapatite but has no hyaluronic acid, so it is firmer on day one and better suited to strong structural work on the jawline and chin, and diluted, to tightening the neck and hands where HArmonyCa is not used.
HArmonyCa is the one to reach for when a defined area, usually the cheeks and jawline, has lost volume and laxity together, and you want to see the change today. For a face after weight-loss injections, that is nearly always the brief. If your concern is skin quality rather than shape, dull or crepey rather than dropped, Profhilo or polynucleotides are a better conversation, and we will say so.
When to treat: during the weight loss or after it?
The instinct is to wait until the weight has stabilised, and for a pure volume filler that instinct is right; there is no point filling a cheek that is still shrinking. A collagen stimulator is different, because the thing you are protecting is the skin's ability to support itself, and that is being lost while the weight comes off. Our approach with patients on our weight management programme is to assess the face at the start and again at each review, and to treat with HArmonyCa once the rate of loss has slowed, typically in the last third of the journey, so the collagen is forming as the last of the fat goes. If you have already finished losing weight, there is no disadvantage to treating now.
What we will not do is treat everyone. If the cheeks are fine and the only issue is a little laxity along the jaw, a smaller product or Radiesse may be enough. If there is significant existing filler, we may ask you to wait. If the laxity is severe, we will tell you that no injectable will do what surgery does, and we would rather lose the booking than the trust.
What the treatment involves, and what it costs
Every HArmonyCa treatment starts with a face-to-face consultation with one of our GMC or NMC-registered medical professionals at least 48 hours before treatment, secured with a £50 deposit that comes off the cost of treatment. The treatment itself takes around 45 minutes. Numbing cream is applied, the product is placed with a cannula on each side of the face, and you leave with written aftercare.
Expect tenderness, swelling and possibly bruising for a few days, and avoid make-up on the area, exercise, alcohol and saunas for 24 hours and firm pressure for a week.
HArmonyCa at Sebastian-Rose is £850 for the full treatment of two syringes, one for each side of the face, with your review appointment included. If we assess at review that a third syringe would improve the result, that is £395. We do not offer a single syringe split across both sides, because it does not give a result we would put our name to. Klarna is available, and you can see how it compares with everything else we offer on our prices page.
All injectable treatments at Sebastian-Rose are performed by GMC or NMC-registered medical professionals holding Level 7 in Aesthetic Medicine, with 24 years of healthcare experience including emergency medicine and over a decade in full-time medical aesthetics. We carry hyaluronidase on site and are members of the Aesthetic Complications Expert Group.
The short version
If you have lost a lot of weight quickly, on injections or otherwise, and your face has paid for it, you have two problems: the volume that has gone and the skin that has lost its support. HArmonyCa is the first product built to address both in one treatment, the 2025 evidence for it is good and specific to this kind of face, and it has real side effects that we will talk you through rather than gloss over. Read the full treatment page at HArmonyCa Cardiff, book a consultation, or call 0800 772 0137. Sebastian-Rose Medical Aesthetics, 39 Charles Street, Cardiff, CF10 2GB.
References
Gritti A, Salomon M, Elmaleh L, Kerson G, Schumacher A. A prospective, open-label, post-marketing study of the safety and effectiveness of a hyaluronic acid and calcium hydroxyapatite hybrid injectable. Journal of Cosmetic Dermatology. 2025;24(9):e70430. https://pmc.ncbi.nlm.nih.gov/articles/PMC12434560/
Proietti I, Spagnoli A, Favaroni A, et al. HArmonyCa hybrid filler to restore connective tissue: an Italian real-life retrospective study. Journal of Cosmetic Dermatology. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11626326/
Fakih-Gomez N, Kadouch J. Combining calcium hydroxylapatite and hyaluronic acid fillers for aesthetic indications: efficacy of an innovative hybrid filler. Aesthetic Plastic Surgery. 2022;46(1):373–381. https://pmc.ncbi.nlm.nih.gov/articles/PMC8831259/
Urdiales-Gálvez F, Braz A, Cavallini M. Facial rejuvenation with the new hybrid filler HArmonyCa: clinical and aesthetic outcomes assessed by 2D and 3D photographs, ultrasound, and elastography. Journal of Cosmetic Dermatology. 2023;22(8):2186–2197.
Braz A, Colucci L, de Oliveira LM, et al. A retrospective analysis of safety in participants treated with a hybrid hyaluronic acid and calcium hydroxyapatite filler. Plastic and Reconstructive Surgery Global Open. 2024;12(2):e5622.
ClinicalTrials.gov NCT07032597. A study to assess safety and effectiveness of HArmonyCa Lidocaine injectable gel for restoration and/or creation of mid-face volume in adult participants. https://clinicaltrials.gov/study/NCT07032597
Save Face. Are you seeing 'Ozempic Face' in your clinic? March 2025. https://www.saveface.co.uk/en/blog/post/are-you-seeing-ozempic-face-in-your-clinic
