M2, M3 or M4 Plus? How to Choose the Right Intraline Filler

For qualified practitioners only

“Which M should I use?”

It’s the question we hear most. It comes up in our inbox, at training days and in the practitioner groups we’re part of. So we thought we’d answer it properly, in one place.

The short answer is simple. M2 Plus is soft and subtle. M3 Plus gives shape and structure. M4 Plus lifts and projects.

The longer answer is in the rheology. Once you understand it, choosing the right product for each area gets a lot easier.

Same HA. Different rheology.

All three products in the M Series are monophasic gels with the same hyaluronic acid concentration, 24 mg/mL. What sets them apart is how each gel behaves once it’s in the tissue. That’s rheology.

Two measurements tell most of the story.

G′ (G prime) is the elastic modulus. It tells you how firm the gel is and how well it holds its shape under pressure. A higher G′ means more lift and support.

Phase angle tells you how elastic or fluid the gel is. A lower phase angle means a more elastic gel that holds its shape. A higher phase angle means a softer gel that spreads and moulds more easily.

Here’s how the three compare.

	M2 Plus	M3 Plus	M4 Plus
G′ (Pa)	37	166	254
Phase angle (°)	28.5	13.1	9.1
HA (mg/mL)	24	24	24
Injection depth	Subcutaneous	Subcutaneous and deep fat	Deep fat, or on the bone
In the tissue	Soft, flexible	Supportive, blends well	Firm, lifting

Independent rheology testing, 2020. G′ measured at 1 rad/s. Phase angle taken from the oscillation stress sweep plateau.

As you move from M2 to M4, the gel gets firmer and more elastic. That’s why each one is placed at a different depth and suits a different job.

M2 Plus: Soft & subtle

M2 Plus is our softest, most flexible filler. It has the lowest G′ and the highest phase angle in the range, so it moves and moulds easily with the tissue. That makes it forgiving in thin skin and delicate areas.

Practitioners use M2 Plus for:

Fine to medium wrinkles, including forehead lines and crow’s feet
Subtle lip definition and the Cupid’s bow
Oral commissures
Neck folds

It’s a lovely choice when the goal is refinement. A little goes a long way.

M3 Plus: Shape & structure

M3 Plus is our medium density filler. Its G′ is more than four times that of M2 Plus, so it gives real shape and support while still blending well.

Practitioners use M3 Plus for:

Medium to deep wrinkles
Nasolabial folds
Marionette lines
Lips that need more structure or volume
Temples and hollows

When folds need softening, or lips need more shape than M2 Plus can give, M3 Plus is usually the one.

M4 Plus: Lift & project

M4 Plus is our highest density filler. It has the highest G′ and the lowest phase angle in the range. It holds its shape well and gives projection with small volumes.

Practitioners use M4 Plus for:

Deep-set wrinkles
Facial contouring of the cheeks, chin and jawline
Non-surgical rhinoplasty
Deep placement on the bone

For structural work, it’s the product many of our practitioners reach for first.

Choosing your M at a glance

What you need	Product	Typical areas
Subcutaneous, refine	M2 Plus	Fine lines, forehead, crow’s feet, Cupid’s bow, subtle lips, oral commissures, neck
Subcutaneous and deep fat, shape	M3 Plus	Nasolabial folds, marionettes, lips, temples
Deep fat or bone, structural	M4 Plus	Cheeks, chin, jawline, nose

If you’re between two products, think about the job. Are you refining, shaping or lifting? In thinner skin, the softer option is usually more forgiving.

Your questions, answered

Do all three contain lidocaine?

Yes. M2 Plus, M3 Plus and M4 Plus all contain lidocaine for patient comfort.

Can Intraline be dissolved with hyaluronidase?

Yes. The M Series is hyaluronic acid based, so, as with other HA fillers, hyaluronidase can be used. Follow your usual protocol and current guidance.

Which needles come in the box?

Each box comes with two needles. M2 Plus has one 27G and one 30G. M3 Plus has two 27G. M4 Plus has one 25G and one 27G.

How much is in each syringe?

Each syringe contains 1.1 mL.

How should I store it?

Store between 2°C and 25°C, out of direct sunlight, and don’t let it freeze. Each product has a shelf life of 24 months from the date of manufacture, so check the expiry date on the box before use.

Is Intraline CE marked?

Yes. The full Intraline range is CE marked.

Where can I order?

You can order directly from us at weareintraline.co.uk once your account has been reviewed and approved, or through our partner pharmacies. Order 10 units of M Series filler in one order, mixing M2, M3 and M4 however you like, and you save the VAT.