Bruising

A bruise is blood that has leaked from a vessel and pooled under the skin. It usually changes colour and clears over days to two or three weeks.

First, why this slot was added late.

When the vitamin K and arnica pages were written on this site, there was no concern for those two ingredients to attach to. Bruising was not on the list. At the time we left both pages with no concern and wrote this: forcing it under 'redness' would read as though these ingredients treat redness, which they do not.

That sentence was right. But the list being empty could not be the reason. So we made the slot and corrected that sentence on both pages. This concern page is a record of the site filling in its own gap.

And this concern differs from the others in one way — it is mostly made by procedures.

It is not a concern about something that arises on its own, like acne or pigmentation. Several procedures on this site record bruising as an adverse effect.

• vascular laser — vessels are the target, so bruising follows
• hyaluronic acid filler and botulinum toxin — a needle goes in
• sclerotherapy — bruising and pigmentation are reported together
• HIFU body contouring — bruising is listed among the adverse events of its sham-controlled trial
• endermologie — it lifts the skin with suction

So if you are here for this concern, the first place to look may be those procedure pages rather than an ingredient. When it appears and how long it lasts is written there.

Now the hardest thing about this concern — it usually clears with nothing done at all.

Which means 'I applied it and it went away fast' cannot be told apart from the passage of time. That is why trial design matters unusually much here. The two trials this site carries either compared the two halves of one person, or made four standard bruises on one person's arms and applied something different to each. That is what cancels out time.

The evidence is thin. Both ingredients rest on one trial each, and for one of them the abstract does not give a participant count. And the arnica in the 2010 trial was 20%, while things sold under the same name include homeopathic dilutions.

Finally, when it is a clinical matter. If bruises appear without a knock you remember, are unusually large, last unusually long, or come easily and repeatedly, establish the cause before choosing something to apply. Clotting, medicines you take and other conditions can all be involved.