Electrolysis: the only method called removal rather than reduction — and the randomised trials are missing

An evidence-based review of hirsutism in Am J Clin Dermatol, 2014, summarising the evidence for the modalities used in premenopausal women.

The authors searched online databases for prior systematic reviews and meta-analyses, and for randomised controlled trials published from 2012 onwards.

Here are the review's own words.

• electrolysis — 'permanent hair removal in localized areas'
• lasers (particularly alexandrite and diode) — 'permanent hair reduction'

Set those two words side by side.

'Reduction' means the hair gets finer and fewer but remains. 'Removal' means the follicle is gone. The difference comes from the mechanism. A laser puts heat into pigment to injure the follicle, so it works poorly on lightly pigmented hair, and injured follicles can recover. Electrolysis puts a needle inside the follicle and destroys it directly.

That is why the word 'removal' attaches only to this method, and why it is used on white, blond and red hair. The laser page sets out the limits on that side.

Now why this entry carries a 'not established' badge.

The review says the evidence supports it. We hold the badge down anyway, because the badges on this site point at trials we have opened and verified ourselves. A review's conclusion goes in the text, not on the badge.

What we carried across is a review's concluding sentence. We have not opened the individual trials behind it. This site holds to a rule of not citing papers from memory and writing only what we verified, so we state our range plainly: what we verified is that the review says this.

We also note that the review itself confines the claim to 'localized areas'. Treating one hair at a time makes large areas impractical.

A 1994 trial at the University of Texas Medical Branch thermolysis clinic in Galveston.

30 women with idiopathic hirsutism of the upper lip took part in a double-blind, placebo-controlled study, and what was measured was pain during treatment, on a 100 mm visual analogue scale.

• 5% lidocaine/prilocaine cream (EMLA) applied before treatment
• placebo cream

Result: the difference in scores was significant (paired t-test, P = .0001). Adverse reactions were mild and transient.

A line from the study's background is worth reading here — fear of pain during treatment may interfere with, or even prevent, treatment on sensitive areas such as the upper lip.

Why this entry is here.

It is not evidence that electrolysis works. This trial did not measure effect. Both arms had electrolysis; the only thing that differed was the anaesthetic cream.

We include it because it is the randomised controlled trial we found for this method. That fact is itself what this page has to report.

One thing this site keeps writing down: no evidence is not the same as no effect. Electrolysis has been in use since long before randomised trials were common, and treating one hair at a time makes a controlled trial awkward to design in the first place.

But the trial does tell us one thing directly: it hurts. The investigators wrote that pain can block the procedure altogether, which is why they tested an anaesthetic cream. That is worth knowing when choosing.

30 people, 1994. Hence 'not established'.