It comes from the manufacturer. The VI Peel FAQ states that the company recommends a series of 3 to 6 peels for optimal results, given every 4 to 6 weeks as directed by the practitioner, followed by around 4 peels a year for maintenance. The body product carries the same 3 to 6 recommendation.
That is a legitimate thing for a manufacturer to publish. It is also the entire source. There is no study behind those numbers. No trial has randomized people to different numbers of VI Peels and measured which group did better, and no published work has tested whether the fourth, fifth or sixth peel adds anything the third did not.
This matters because a course of six peels is a much larger commitment than one, both in money and in weeks of visible peeling. It is reasonable to ask a provider what specifically they expect each additional session to change.
One paper exists on any VI Peel, published in the Journal of Drugs in Dermatology in 2024. It was single-arm and open-label with 30 participants across Fitzpatrick skin types I to VI. There was no control group, no comparison peel, no randomization and no blinding — and the paper's conflict-of-interest statement is not publicly retrievable, while the manufacturer distributes the paper itself as marketing material. Read it as company-adjacent evidence.
Each participant received a VI Peel followed by botulinum toxin on the same day. The stated purpose was to check whether that same-day combination was safe, not to measure what the peel does. No adverse events were reported. Scores improved: wrinkle severity by 60%, uniformity of pigment by 59%, skin tone by 70%.
Three things follow for anyone asking about a course.
The wrinkle number cannot be credited to the peel, because botulinum toxin reduces wrinkles on its own.
The pigment and tone numbers are not confounded by the injections in the same way, but they come from 30 uncontrolled patients with nothing to compare against, and the abstract does not state at what point after treatment the assessment was done.
And it was one peel, not a series. So even this study says nothing about how many peels anyone needs.
None of this makes the product ineffective. Perfect Derma Peel and BioRePeel, two other widely sold branded peels, have no indexed peer-reviewed studies at all. Thin evidence is the norm across this category rather than a mark against this brand.
Here is the honest split between what is fairly well established and what is being inferred.
Reasonably well established. A single peel of this general type produces one cycle of shedding. Peeling typically starts on or around day 3 and is generally finished by about day 7. What people usually report at the end of it is smoother surface texture and brighter skin. That is a real effect of removing the outer layer, and it happens after essentially any peel.
Reasonably well established. That single-peel effect is temporary in the sense that skin keeps producing new surface layers and keeps being exposed to whatever caused the problem — sun, hormones, oil, friction.
The reasoning behind a series, which is plausible but untested for this product. Deeper problems do not sit in the layer a single peel removes. Melasma, post-inflammatory hyperpigmentation (dark marks left after a breakout heals) and acne scarring are held in deeper skin, and the usual clinical approach is repeated, controlled injury over months rather than one aggressive treatment. Repeat sessions also let a provider see how your skin responded before deciding what to do next.
That is sound reasoning. It is not a measurement of this product.
Peel trials that do get published tend to look like this:
Two patterns stand out. Session counts cluster at 3 to 6, which lines up with the manufacturer's recommendation. Intervals cluster at 2 weeks, which does not.
The likely explanation is straightforward: those trials used single superficial acids, which are light enough to repeat quickly. A product presented as medium-depth needs longer between sessions. That explanation is reasonable, but because VI does not publish concentrations for any of its products, no one outside the company can confirm where this peel actually sits on that scale.
There is also a broader finding worth carrying into any conversation about a course. A systematic review of peel-against-peel trials in acne pooled 12 randomized trials covering 387 people in total. Across most comparisons — trichloroacetic acid against salicylic, glycolic against salicylic, glycolic against Jessner's solution — there was no meaningful difference between agents. The authors described the methodological quality of the included trials as very low to moderate and concluded that no robust conclusion about the superiority of any peel could be drawn.
In other words: peels generally do something, the differences between them are smaller than the marketing suggests, and the trials are small.
Since no number of sessions is evidence-based for this product, the practical approach is to measure rather than to count.
Take photographs before the first peel. Same room, same light, same distance, no makeup, three angles. Repeat them about four weeks after the third peel, at the same time of day.
Decide in advance what you are treating. Uneven tone, active breakouts, dark marks and rough texture respond on different timelines. "My skin looks better" is hard to check a month later. "The dark marks on my left cheek" is not.
Expect the least from scarring. Textural acne scarring is the hardest of these targets, and it is the one where other approaches have outperformed peels in head-to-head trials. In a randomized trial of 60 people with acne scars in Fitzpatrick skin types IV to VI, microneedling produced meaningful improvement in 73% compared with 33% for a 35% glycolic acid peel.
Re-evaluate at three sessions, not at six. If your provider cannot point to a specific change after three peels, that is the moment to ask what the next three are expected to do differently.