Fat dissolving injections: guide and aftercare

Fat dissolving injections occupy an awkward place in aesthetics: genuinely useful for the right patient, heavily oversold to the wrong one. The treatments work, the swelling is real, the sessions are multiple, and none of that is a problem if the consultation is honest. This guide covers how the treatments work, who they suit, what the recovery actually looks like, and includes a complete aftercare sheet you can adapt and send to your own patients.

How fat dissolving treatments work

Most injectable fat dissolving products are based on deoxycholic acid or similar compounds, substances that disrupt the membranes of fat cells in the treated area. The damaged cells are then cleared gradually by the body’s own processes over the following weeks. Different branded products exist with different formulations and licensing statuses, so this guide describes the category generically; practitioners should know the specific product they use, its regulatory status and its protocol thoroughly.

Two consequences follow from the mechanism. First, results are gradual: the fat is cleared over weeks, not dissolved on the day. Second, the process of breaking down fat cells is inherently inflammatory, which is why significant swelling is a normal and expected part of treatment rather than a complication.

Suitable areas and suitable patients

The classic treatment area is the submental region, the pocket of fat under the chin, and this remains the best-evidenced use. Practitioners also treat small, stubborn, localised pockets elsewhere, such as the jowls, bra-line area, inner thighs or lower abdomen, depending on the product’s intended use and their own training. Small and localised is the operative phrase: these are contouring treatments for discrete pockets of pinchable fat in patients close to a stable, comfortable weight.

Good candidates have a specific pocket they can point to, reasonable skin quality that will retract as the volume reduces, realistic expectations and a stable weight. Poor candidates include patients with loose skin that needs the fat for support, patients whose concern is generalised rather than localised, and anyone seeking weight loss.

Multiple sessions are the norm

One session rarely completes the job. Most patients need a course of treatments, commonly two to four sessions spaced several weeks apart, with the exact number depending on the product, the area and how much fat is being treated. Each session treats a portion of the fat, the body clears it, and the next session builds on the result. Price and plan the course honestly at consultation: a patient quoted for one session who turns out to need three will reasonably feel misled, while a patient who books a course knowing the realistic range will judge progress fairly.

The consultation honesty piece

The single most important sentence in a fat dissolving consultation is some version of: this is not a weight loss treatment. It removes a small, localised pocket of fat for contouring; it does not change overall body weight in any meaningful way, and it is not appropriate as a response to general weight concerns. Patients seeking weight loss should be redirected, kindly, towards their GP or appropriate services.

The second most important is the swelling conversation. Patients should expect the treated area to swell noticeably, sometimes for days and occasionally for a few weeks, and to look worse before it looks better. A submental patient may not want treatment a fortnight before a wedding. Cover the multi-session reality, the gradual timeline, tenderness, bruising, temporary numbness and lumpiness, and for submental work the rare but serious risks the product literature describes, including nerve-related weakness affecting the smile. Document the discussion, take baseline photographs, and use a treatment-specific consent form. Record the product, batch number, expiry, volumes and injection sites for every session, as set out in our licensing-ready records checklist.

The aftercare sheet

The text below is written to be sent to patients. Adapt it to your own protocol and product before use.

Your fat dissolving treatment is complete. Swelling and tenderness are an expected part of how this treatment works, so please read this guidance and keep it for the days ahead.

What to expect

• Swelling in the treated area is normal and expected. It is often most noticeable in the first few days and can take days to a few weeks to settle fully. The area may look fuller before it looks slimmer.
• Tenderness, warmth, firmness, bruising and temporary numbness in the area are all common and settle over time.
• Results are gradual. Your body clears the treated fat over the following weeks, and most courses involve more than one session. Judge your result at the timescale your practitioner described, not in the first fortnight.

For the first 48 hours

• Avoid alcohol.
• Avoid strenuous exercise. Gentle walking is fine; the gym is not.
• Avoid saunas, steam rooms, sunbeds and very hot showers.
• Do not massage or press on the treated area unless your practitioner has specifically advised massage as part of your protocol.
• Keep the area clean, and avoid makeup or products directly over injection sites until they have closed.

In the days that follow

• A cool compress, used gently and not directly on bare skin, can help with comfort and swelling.
• If your practitioner has advised a compression garment or chin strap for your treatment area, wear it as directed. Compression is commonly advised for some areas and not others, so follow your own practitioner’s instruction rather than general advice.
• Sleep with your head raised on an extra pillow for the first few nights if the treated area is on the face or neck; many patients find this more comfortable.
• Stay well hydrated and avoid pressing, prodding or repeatedly checking the area.

Contact your practitioner urgently if you notice

• Any change in the colour of the skin over the treated area, such as blanching, mottling, darkening or a developing wound, blister or ulcer.
• Severe or worsening pain, or swelling that increases sharply after initially settling.
• Spreading redness, heat, fever or feeling generally unwell, which can indicate infection.
• Weakness in the area, such as an uneven smile after under-chin treatment, or difficulty swallowing.
• Anything that feels wrong and is not covered here. A message with a photograph is never a nuisance; it is what your practitioner wants you to send.

Consent, records and follow-up

Because courses span months and swelling obscures early judgement, fat dissolving treatments lean harder on documentation than most injectables. Photograph at baseline and before each subsequent session under consistent lighting, record the product and batch details every time, and note the patient’s own report of how the previous session settled. A written consent covering the not-weight-loss point, the swelling expectations and the multi-session plan is what protects both parties when a patient’s memory of the consultation differs from yours.

Managing a multi-session course is also an administrative problem: session spacing, course payments, photo comparisons and aftercare follow-ups all need tracking. AesthetiClinic handles course bookings, stores photographs and consents against the patient record, and sends aftercare and follow-up messages automatically, so the third session is as well documented as the first. See our features page for the details.

General aftercare guidance for UK aesthetics practice. Your practitioner’s specific advice always takes precedence. Patients with urgent symptoms should contact their practitioner or seek medical care immediately.