Fat dissolving injections, including Aqualyx, reduce small, stubborn pockets of fat gradually. You will not see a change overnight, and a single session rarely finishes the job. Results build over several weeks as your body clears the treated fat cells, and most areas need a short course of sessions spaced at least four weeks apart. This guide sets out what the evidence says about results, timing, session numbers and side effects, so you can decide with realistic expectations.
TL;DR
- Fat dissolving is a body-contouring treatment for localised fat, not a weight-loss treatment.
- A published review reported average effectiveness of around 76% across treated zones, with results varying by area and patient.
- Studies describe courses of several sessions, with at least four weeks between them.
- Swelling and redness are expected and usually settle within days to two weeks; choose a medically trained, CQC-registered practitioner.
- Our published prices for fat-reduction treatments start at £300, and we assess you in a consultation first.
Table of Contents
- What fat dissolving can and cannot do
- How effective are fat dissolving injections?
- How long until you see results?
- How many sessions will you need?
- What affects how your results look
- Side effects and recovery
- Fat dissolving versus weight loss treatments
- How much does fat reduction cost with us?
- What a good consultation covers
- Our perspective
- Book a fat dissolving consultation
- FAQ
- Sources
What fat dissolving can and cannot do
Fat dissolving injections target small areas of fat that resist diet and exercise: under the chin, the jawline, the lower abdomen, the flanks, the inner thighs. The most common injectable is Aqualyx, a deoxycholate-based product. A February 2026 clinical review in Aesthetic Medicine describes it as a tool for localised fat rather than a weight-loss solution, and stresses realistic expectations and careful patient selection.
That framing matters for how you judge results. A good outcome is a smaller, better-defined pocket of fat in the area we treat. It is not a lower number on the scales. If you are looking to lose a significant amount of weight, fat dissolving is the wrong starting point. If you are at a steady weight and one area refuses to change, it may be a good fit.
The treatment works by injecting a solution into the fatty layer under the skin. The solution damages the membranes of the fat cells, and your body then clears the contents through its natural processes. This is why the change is gradual rather than immediate.
How effective are fat dissolving injections?
The published evidence points to a meaningful but variable effect. A 2016 peer-reviewed review of intralipotherapy, the broader family of fat-dissolving injections, reported average effectiveness of 76.7% across treated zones, while noting that results differed by treatment area and by patient. The February 2026 Aesthetic Medicine review quotes a similar average success rate of 76% across sites and numbers of treatments.
What does that mean in practice? Three things shape your result:
- The area. Small, well-defined pockets such as under the chin respond differently from larger areas such as the abdomen or flanks.
- The thickness of the fat. Fat that can be pinched is the target. Deeper fat around the organs cannot be reached by this treatment.
- Your starting point. Skin quality, lifestyle and how you respond all play a part. We discuss this in your consultation rather than promise a figure.
The same review of the technique concludes that standardised technique, protocol and aftercare are important for consistent results and fewer adverse events. In other words, who treats you and how matters as much as the product.
How long until you see results?
You should not expect a visible change in the first days. Straight after treatment, swelling can hide any early difference. The 2016 review describes treatment-related oedema peaking between six and 24 hours and generally reducing or disappearing by 72 hours in the imaging observations it reports.
Once the swelling settles, a typical pattern looks like this:
| Stage | What happens |
|---|---|
| First 24 to 72 hours | Swelling, redness, tenderness and possible bruising in the treated area |
| Up to around 2 weeks | Swelling and redness can linger; the February 2026 review names swelling and redness lasting up to 14 days as the main usual effects |
| Following weeks | Your body gradually clears the treated fat cells and the contour starts to refine |
| At least 4 weeks | Earliest sensible point for a review and, if needed, a further session |
A useful way to think about it: the first visible change comes once the swelling has gone, and the full effect of a session takes weeks to develop. The 2016 review notes that the tissue effects continue after treatment, which is why it recommends waiting at least four to seven weeks between sessions, depending on the area, your response and the quantity used.
That is also the answer to how long Aqualyx results take: expect the first meaningful change over the weeks after a session, and judge a course only once the full gap between sessions has passed.
How many sessions will you need?
The honest answer is that it depends on the area, and your practitioner should say so after examining you. The research gives useful reference points:
- A 1,269-patient series using phosphatidylcholine and deoxycholate reported an average of four sessions at four-week intervals, with assessment eight weeks after the last session. The same study found the greatest improvement was generally achieved in the first session, although one or two further sessions could be needed.
- A peer-reviewed body-sculpting report advised that around three to four treatments per area may be needed, and recommended reassessing an area six weeks after the first treatment.
- The 2016 review illustrates Aqualyx outcomes after two sessions for lumbar fat and five sessions for saddlebag thighs, flanks and back rolls.
For a small area such as the chin, fewer sessions are often discussed than for a larger area such as the stomach. For the stomach, plan for a course rather than a single visit. Our guide to dissolving chin fat safely and effectively covers the smaller area in more detail.
Why spacing matters
Treating too soon means injecting into tissue that is still responding. The February 2026 review says the cell-breakdown process can continue for several weeks, which supports intervals of at least four weeks. A clinic that offers back-to-back sessions in the same week is not following this guidance.
What affects how your results look
Two people can have the same treatment and see different outcomes. These are the factors we look at in a consultation:
- Treatment area and fat thickness. Pinchable, localised fat responds best.
- Skin quality. Where skin is loose, removing fat can make laxity more noticeable. In some cases we discuss pairing fat reduction with skin-tightening or skin-quality treatments such as Profhilo or Sunekos.
- Lifestyle and weight stability. Steady habits help you keep a refined contour. Significant weight gain can change how any area looks, so it is worth discussing your plans with your practitioner.
- Practitioner skill. A 145-patient Aqualyx series recorded nodules in 42% of patients, and 53 of the 61 patients with nodules had been treated by less-experienced doctors. Experience shows in the outcome.
- Following aftercare. Managing swelling properly keeps you comfortable and helps you judge your result sooner.
Side effects and recovery
Results are only half of the picture. Fat dissolving causes an inflammatory reaction by design, so some effects are expected.
Common and expected. A 2022 peer-reviewed case report lists swelling, redness, pain and bruising as the common effects of deoxycholate injections. A BAAPS abstract of a systematic review covering 28 studies and 1,472 participants reported swelling in 85%, redness in 70% and tenderness in 65%.
Nodules. Lumps can form in the treated area. The same BAAPS abstract reports that most nodules are self-limiting, with most resolving by four months and generally decreasing within six months. Tell your practitioner if you notice a lump, or if redness, heat or pain worsens rather than eases.
Rare but serious. The BAAPS abstract describes skin or muscle necrosis and injury to nearby nerves or vessels as serious complications, with nerve injury at 2% and difficulty swallowing at 1.5% reported as rare severe events. This is exactly why treatment belongs with a trained medical professional who knows the anatomy, particularly around the chin and neck.
Use only approved, properly sourced products
The US FDA warns that unapproved fat-dissolving injections, including products marketed as Aqualyx, have been linked to reports of permanent scars, serious infections, skin deformities, cysts and deep painful knots. That is a US regulator speaking about the US market, but the lesson travels: ask who is treating you, what product they are using and where it came from. Never buy fat dissolving products online for self-injection, and avoid beauty salons and pop-up events where nobody can show you medical credentials.
Looking after the area afterwards
Swelling is the part you can manage. Our guide to reducing post-treatment swelling safely covers the practical steps, and we explain how lymphatic drainage may help with swelling in a separate article. Follow your practitioner’s own instructions first, as they depend on the area treated.
Fat dissolving versus weight loss treatments
People often search for fat dissolving when they really want to lose weight, so it helps to be clear. Fat dissolving reduces fat in a defined spot. Weight-loss approaches change your overall body weight. The two are different goals, and a treatment designed for one will not deliver the other. If your priority is overall weight, speak to your GP first. If your priority is refining a specific area at a stable weight, a consultation about fat dissolving or a device-based option such as Em-Shape is the sensible next step.
How much does fat reduction cost with us?
We publish our prices on our price list. For fat-related treatments they currently read:
| Treatment | Price |
|---|---|
| Green Laser, Fat Dissolving | £300 |
| Em-Shape | £300 |
| Jawline Slimming | £350 to £390 |
| Jaw Definition & Contouring | £310 |
Because a course usually means more than one visit, ask at your consultation how many sessions your area is likely to need, so you can see the full cost before you start. Cost is only one part of choosing a clinic; the practitioner’s training and the clinic’s regulation matter more. Our guide to London aesthetic consultations lists what to ask.
What a good consultation covers
Before any injection, expect your practitioner to:
- take a medical history and ask about medication, allergies and previous treatments;
- examine the area and confirm that it is localised, pinchable fat rather than loose skin or deeper fat;
- tell you what a realistic outcome looks like and how many sessions it may take;
- explain the side effects above in plain terms, including what to do if something feels wrong;
- name the product they will use and explain where it is sourced.
If you would rather start from home, we also offer virtual consultations, and we always advise an in-person assessment before treatment.
Our perspective
Most disappointment with fat dissolving comes from the wrong expectations, not from the treatment itself. Patients who arrive hoping for a dramatic change in one visit leave frustrated. Patients who understand that this is a gradual, planned course tend to be far happier.
We take a medically led, bespoke approach. That means we look at the whole picture: the area, your skin, your habits and your goals. Sometimes the right plan is fat reduction alone. Sometimes it is fat reduction alongside skin-quality treatments so the area looks smooth and firm as well as slimmer.
Safety comes first. We are CQC-registered and members of the ACE Group, which is dedicated to patient safety, and every treatment is performed by medically trained professionals. We would rather spend an extra ten minutes on your consultation than rush you into a treatment that is not right for you.
Vishul
Book a fat dissolving consultation
If you are considering fat reduction in London, we will assess the area, explain your realistic options and build a plan around you. Our clinics are in Knightsbridge, Harley Street and Mayfair, and you can see every treatment and price on our price list, or book through our website.
We will tell you honestly whether fat dissolving suits you, and what else might work better if it does not.
FAQ
How long do Aqualyx results take to appear?
Swelling usually hides any change for the first days and can last up to around two weeks. After that, the contour refines gradually over the following weeks as your body clears the treated fat cells. Judge your result only after the gap before your next session has passed, which is at least four weeks.
How many fat dissolving sessions do I need for my stomach?
The stomach is a larger area, so expect a course rather than one session. Published series describe averages of around four sessions at four-week intervals, and a body-sculpting report suggests three to four treatments per area. Your practitioner should give you a personal estimate after examining you.
How effective is Aqualyx?
A 2016 review reported average effectiveness of 76.7% across treated zones, with results varying by area and patient. It works on localised fat and is not a weight-loss treatment. Choosing an experienced, medically trained practitioner is one of the biggest factors in a good outcome.
What are the side effects of fat dissolving injections?
Swelling, redness, tenderness and bruising are expected, and most settle within days to around two weeks. Nodules can appear and usually resolve within months. See a medical professional promptly if pain, redness or heat increases, or if you have trouble swallowing after a chin or neck treatment.
Sources
- BODY OF EVIDENCE, Aesthetic Medicine, February 2026
- Intralipotherapy, the State of the Art (PubMed)
- Intralipotherapy, the State of the Art (PMC)
- Injection Lipolysis: A Systematic Review of Literature
- Lipodissolve for Body Sculpting
- Chronic Infection and Nodule Formation following deoxycholate injections
- The Hidden Perils of Slimming Shots, BAAPS abstract
- FDA: Using Fat-Dissolving Injections That Are Not FDA Approved
