Micro-toxin skin injections:
intradermal micro-dosing for oil, pores and fine lines, and how it differs from muscle injections

What are micro-toxin skin injections, and what do they aim to change?

Micro-toxin skin injections use the same prescription-only botulinum toxin as wrinkle injections, but prepared at a much higher dilution and placed differently. Instead of a few deeper deposits into a chosen muscle, a large number of very small deposits are placed shallowly within the skin across an area such as the forehead, the cheeks, the nose, the lower face or the neck. Each deposit carries a tiny fraction of the dose that a muscle injection would, and the deposits are spaced closely so that the skin, rather than any one muscle, is the target.

Three structures in the skin respond to botulinum toxin. The eccrine sweat glands are driven by the same chemical messenger that drives muscle, which is why toxin is used for excessive sweating; quietening them reduces surface moisture and the shine that goes with it. The arrector pili, the tiny muscles attached to each hair follicle and its oil gland, are also quietened, and small studies report a reduction in sebum output and in the visible size of pores afterwards, although the mechanism is not fully settled. Finally, the most superficial fibres of the muscles of expression, which insert into the underside of the skin and crinkle it into fine lines, receive a little of the medicine, so the fine surface lines of the forehead, the crow's feet region and the neck soften while the deeper, stronger part of each muscle keeps working.

The changes small studies describe, where they occur, are less oil, smaller-looking pores and a smoother surface at rest. It is temporary, because the medicine is, and it is modest, because the dose is. People searching for micro-toxin in Singapore usually find it described alongside skin boosters, and the two are often confused: skin boosters add a substance to the skin, micro-toxin reduces the activity of structures already there.

How do micro-toxin skin injections differ from wrinkle injections into the muscle?

The product is the same; everything else is different. The table sets out the contrasts that matter when deciding which one a concern calls for.

Two consequences follow. A person with strong frown or forehead lines on expression will not get the answer they want from micro-toxin, because the deep muscle that makes those lines is deliberately left working; that is a wrinkle injection question, and the suitability rules on the botulinum toxin suitability page apply. Conversely, a person with oily skin and open pores who has no dynamic lines gains nothing from muscle injections. Many people have both concerns, and the two approaches are sometimes used together on the same face in different zones, which is a planning decision made at assessment.

Because the medicine is placed shallowly across a wide area, the risk that is most specific to micro-toxin is the opposite of the one people fear: not too little effect, but medicine reaching a muscle it was not meant to reach. On the forehead a generous intradermal grid can still weaken the frontalis enough to lower a brow that was relying on it, and on the lower face it can soften the muscles around the mouth. That is why the forehead is treated cautiously in anyone whose brows sit low and why the lower face is mapped around the mouth rather than across it.

“Micro-toxin quietens the oil gland. It does not rebuild the wall of the pore, and it does not fill a scar.”

Dr Sin YongOn what intradermal toxin can and cannot change

Who suits micro-toxin skin injections, and who does not?

The treatment is aimed at a narrow set of concerns and does not address a wide set of others. The table is a guide to the assessment rather than a substitute for it.

Oily skin and enlarged pores have their own pages on this site, oily skin treatment and uneven texture and large pores, and those pages set out the treatments the clinic uses for them. Micro-toxin, where it is offered, sits beside those rather than in place of them, and a person whose pores are enlarged because of scarring or because of sun-damaged collagen around the pore will be pointed to resurfacing or collagen stimulation instead, because quietening the oil gland does not rebuild the wall of the pore.

What are the limits and side effects of micro-toxin skin injections?

The limits are worth stating plainly because the treatment is often described online as if it did everything. It does not treat acne scars, which are a collagen problem; it does not lighten pigmentation; it does not shrink pores that are enlarged because of scarring; it does not lift, tighten or add volume; and it does not remove a static crease that is present at rest, because that crease is in the skin's collagen, not in a muscle. The reduction in oil is modest and temporary. Someone with severe oily skin or active acne is treated for that condition first, with the approaches on the acne treatment page, and micro-toxin is at most a later refinement.

The evidence base is small. Published series and small controlled studies report reduced sebum, smaller-looking pores and smoother texture after intradermal toxin, with the effect wearing off as the medicine does, and the reviews that summarise them call for larger trials. It is a use outside the registered indications of the products, which in Singapore are prescription-only medicines registered with the Health Sciences Authority for named uses. Off-label prescribing on a doctor's judgement is permitted, but it means the person should be told that the evidence is modest and the use is off-label, and should be asked to consent on that basis.

Side effects are mostly those of many small injections: pinpoint bleeding, small bruises, transient redness and a sensation of tightness for a short period. The effects that matter are from medicine reaching a muscle: a heavier brow or a lowered brow after forehead treatment, an asymmetric smile or a change in lip movement after lower-face treatment, and, on the neck, difficulty with swallowing or neck flexion if the dose is generous. These are temporary but last as long as the medicine does. Rare risks include infection, an allergic reaction, and a flare of cold sores in people prone to them. Anyone who develops difficulty swallowing, breathing or speaking should contact the clinic the same day.

How this concern is approached at the clinic, and what decides the plan

Whether micro-toxin skin injections are offered for a particular person is confirmed at consultation, after Dr Sin Yong has examined the skin in person: under bright light and magnification for oil and pore pattern, at rest and in expression for the lines, and with the brow checked against the bony rim before the forehead is considered. Every treatment on this site is doctor-performed after an in-person assessment, and no plan is written from photographs. The first decision is whether the concern is oil and surface texture, which micro-toxin can address, or scarring, pigmentation, laxity or volume, which it cannot; the second is whether a dynamic line is the real complaint, in which case muscle injections are the right tool.

What decides the plan, once the concern fits, is a short list of factors rather than a menu. The area to be covered sets the number of points and therefore the total dose. The strength of the underlying muscle, and how much the person relies on it, sets the dilution and how far the grid is kept from the brow and the mouth. Skin thickness decides the depth of each deposit, which is shallower on thin skin. Any previous botulinum toxin, with product, dose and date, is recorded because units are not interchangeable and because a recent muscle treatment changes what the skin treatment can safely add. Fees are set in writing after assessment; the factors behind them are on how fees are quoted.

Aftercare is simple in outline: the area is left clean and untouched on the day, make-up is paused briefly, heat, saunas and facials are avoided until the skin has settled, and the face is not massaged, so that the medicine stays where it was placed. The review compares the skin under the same light as the assessment and decides whether the treatment did what it was meant to, whether a different concern was the real author, and whether repeating it is worth the person's money.