Why phototype changes the treatment, not just the risk
A laser does not distinguish between pigments out of goodwill: it does so by physics. The light targets a chromophore — the molecule that absorbs it — and for veins that chromophore is haemoglobin. The absorbed energy becomes heat, the vessel wall passes coagulation temperature, and the body reabsorbs the closed vein.
The problem on darker skin is that epidermal melanin competes for that same light. If the device or the fluence is not matched to the phototype, part of the energy stays in the skin instead of reaching the vessel — hence the risk of hyper- or hypopigmentation that gave the method its bad name.
So "laser stains darker skin" is a half-truth. A protocol copied from an American or European paper, written for phototypes I and II, can indeed cause pigment change here. The same method at the right device and fluence for phototype IV is a different matter. Most of the Mexican population sits at phototypes III to V, and deserves a protocol written for their skin.
Two devices for two calibres: the most common error
This is the point most often got wrong, and the one worth asking about at your consultation. The device is chosen by vessel thickness — not by clinic preference, and not by whichever machine happens to be free.
- Intense pulsed light (IPL) — for fine vessels, 0.4 to 1 mm. In the subgroup of 25 patients aged 26 to 45, the best results came with the 570 nm filter, applied over two or three pulses.
- Nd:YAG 1064 nm laser — for telangiectasias larger than 1 mm and reticular veins. It is the wavelength that penetrates deepest and interferes least with surface melanin, which is precisely why it is the indicated device on darker skin. In the subgroup of 138 patients aged 20 to 70, fluence was stepped by calibre: lower for telangiectasias, higher for reticular veins, with two passes rather than one on the thickest reticular vessels.
How many sessions, and why this is not a one-visit treatment
Sessions are spaced about two months apart and repeated until the intended result is reached. The interval is not administrative: a treated vein does not vanish the same day — it closes, and the body reabsorbs it over weeks. Assessing too early leads to over-treating an area that was still improving.
If someone offers to clear a pair of legs in a single session, that offer describes a sales calendar, not a biological process.
What improvement is realistic
In the Nd:YAG group, improvement was 80 to 85%. That is the honest figure, and it is worth comparing against what advertising promises: it is not 100%, and it is not 100% in any serious series.
One more finding that is part of the result: two patients discontinued treatment because of pain during the procedure. It is a real discomfort, tolerable for most, but not trivial — and better known before you start than discovered on the table.
Individual factors mean not every patient obtains the same result. Session count and settings are defined after an in-person consultation. Results may vary.
What laser does not solve — and this is the important part
Here is the part that changes the two-year result and almost never appears in an advertisement.
Visible spider veins are the surface of a system. The deep venous network handles around 80% of the leg’s venous return, and the perforating veins connecting it to the superficial network can have damaged valves and lose one-way flow. When that happens, it is called venous insufficiency.
If underlying venous insufficiency is present and only the visible spider veins are treated, the result is temporary: they come back. Not because the laser failed, but because a symptom was treated. That is why a proper assessment includes study of the venous system, not just looking at the leg.
Laser is an effective, non-invasive therapy, and it can be combined with other procedures — sclerotherapy, or endovenous laser treatment (EVLT) — when the underlying problem calls for it. The question worth asking in consultation is simple: is anyone going to investigate why these appeared?
Risks, named plainly
Pain during application — the most frequent reason for discontinuation — transient redness and swelling, and crusting. On darker skin, additionally, a risk of temporary hyper- or hypopigmentation.
That risk is minimised in two concrete ways: matching fluence to phototype rather than applying a setting from a protocol written for fair skin, and avoiding sun exposure between sessions. The second one is up to you, and it is the one most often ignored.
What this looks like in consultation
A proper assessment for leg veins includes determining your phototype, measuring the calibre of the vessels to be treated, reviewing the venous system, and explaining which device applies and why. Session count and settings follow from that, not the other way around.
You can see the full procedure at varicose and spider veins, and if you want the criteria worth applying to any surgeon — including the author of this guide — they are set out in how to choose a plastic surgeon in Puebla.
Frequently asked questions
Does vein laser cause pigment marks on darker skin?
It can, if fluence and device are not matched to the phototype. That is exactly the risk controlled by choosing the Nd:YAG 1064 nm laser, which interferes less with surface melanin, by matching energy to phototype, and by avoiding sun exposure between sessions. In a series of 163 patients with phototypes III, IV and V, both intense pulsed light and Nd:YAG proved valid options on darker skin.
How many sessions do leg spider veins need?
Several, spaced around two months apart, until the intended result is reached. This is not a one-session treatment: a treated vein does not disappear the same day — it closes and the body reabsorbs it over weeks. The exact number depends on calibre and extent, and is defined at consultation.
Do leg spider veins go away completely?
Not completely. In the Nd:YAG group, improvement was 80 to 85 per cent. Any offer of total elimination is advertising. And if underlying venous insufficiency is present and never investigated, spider veins can reappear even when the treatment was performed correctly.
Why do my spider veins come back after treatment?
Most often because underlying venous insufficiency is present. The deep veins handle around 80 per cent of venous return, and perforating veins can lose one-way flow through valve damage. If only the visible vessels are treated and the venous system is never studied, the result is temporary. That is why assessment must include it.
Is laser treatment for leg veins painful?
There is discomfort during application, and it is the most frequent reason patients discontinue: in the series of 163 patients, two stopped for that reason. Most people tolerate it well. It is worth knowing beforehand and raising at consultation so pain management can be adjusted.
What is the difference between IPL and Nd:YAG for leg veins?
Vessel calibre. Intense pulsed light matches fine vessels of 0.4 to 1 mm. The Nd:YAG 1064 nm laser matches telangiectasias larger than 1 mm and reticular veins, and it also interferes least with melanin, which makes it the indicated device on darker skin. Choosing by whichever machine is available rather than by vessel calibre is the most common error.
Every case is different. Get your questions answered in a personal consultation.
Book a consultation on WhatsAppEvery figure published on this site is approximate and is not a quote. Any procedure or treatment first requires a private assessment consultation with Dr. Arístides Arellano —$800 MXN, charged separately— and it is at that consultation that the definitive cost of your case is determined.
Educational content; it does not replace a medical consultation. Results may vary from person to person.