Carboxytherapy: it tied with vascular laser on red stretch marks — and in the ageing trial, participants lost weight

A 2026 split-side trial in Egypt, in 20 patients with red stretch marks (striae rubra).

First, what red stretch marks are. Stretch marks start out red or purplish. That is the stage while the vessels are still live; with time the colour drains and they become white marks (striae alba). Both procedures target the vascular component of this red stage.

• On each patient, vascular laser (PDL) on one stretch-marked side and carboxytherapy on the other — assigned at random
• Assessed by: number of striae, maximum stria width, Vancouver Scar Scale (VSS), erythema index (EI) and histopathological evaluation

The results.

• Both modalities improved significantly in VSS, EI and histopathological scoring
• Comparing the two against each other, there was no significant difference in VSS, EI or histopathological change

That the histology diverged is interesting.

• Vascular laser: collagen and elastic fibres increased significantly
• Carboxytherapy: collagen fibres and perpendicular blood vessels increased significantly

The surface scores came out the same while what happened in the tissue differed. It is the opposite shape from the exosome page, where the histology was the same on both sides.

The authors' conclusion carries one more line. They propose that vascular laser produces a better outcome for texture, and record that post-inflammatory hyperpigmentation was encountered following the laser, with that risk avoidable at a proper dose.

Twenty people, and the abstract gives no number of sessions or follow-up period. We left those fields blank.

And the shape of the conclusion is familiar here — A versus B, no difference. The third item below is about that.

A 2024 trial in intrinsic ageing of the abdomen. Twenty-eight patients completed it (mean age 44.13). The design is described as 2-split randomised.

The results first.

• Subjective and objective evaluation showed significant improvement in wrinkles, laxity, pigmentation and overall satisfaction
• Epidermal and dermal thickness increased significantly on ultrasound
• No significant side effects were reported by the subjects

Measuring thickness by ultrasound is a good condition. As the radiofrequency plus HIFEM page sets out, an instrument reading does not pass through expectation and lighting.

But the abstract carries one more line.

The participants' mean weight, BMI and waist circumference significantly decreased after the treatment.

That single line shakes everything above it.

Consider what this trial assessed: the skin of the abdomen — wrinkles, laxity, thickness. And the participants' waists got smaller.

When someone loses weight, abdominal skin changes regardless of any procedure. Which way it changes is not one-directional — skin that was taut can slacken, or swelling can subside and the texture look better. Either way, that change does not belong to carboxytherapy.

Why the weight fell is not in the abstract. It might be the procedure (a claim that would need separate verification), or it might be that joining a trial changed what people ate and how they moved. That enrolment alone changes behaviour is a well-known phenomenon.

So this item is filed as 'not established'. What is not established is whether the change in skin belongs to the procedure.

The cryolipolysis page carries a similar sentence — there, weight change over 12 weeks was absent from the abstract entirely. Here it is present, and recorded as significantly decreased. That they wrote it down is, if anything, to their credit.

The comparators in the two trials above were vascular laser and the opposite site on the same person.

There was no untreated side, and no side that received the needle without the gas.

Designing a sham here is a particularly interesting problem. Carboxytherapy inserts a needle and injects gas. So a sham would be the needle without the gas. But as the PRP page showed, the needle going in does something to skin by itself — in that trial, blinded assessors could not tell the saline cheek from the PRP cheek.

We found no trial making that comparison for carboxytherapy.

So, restating what is established:

• It was indistinguishable from vascular laser on red stretch marks — established
• Collagen and vessels increased in the tissue — established
• Skin measures improved in the abdominal ageing trial — established, but weight fell too
• Whether injecting gas beats inserting the needle alone — not established
• Whether it beats doing nothing — not established

And this site now has two pages covering red stretch marks — this one and vascular laser. In the trial above the two tied, and the authors proposed the laser as better for texture while recording that pigmentation appeared on the laser side. Which to prefer is something to weigh between the two.