ASTRAL CODEX TEN
1: What is silexan?
There are dozens of natural supplements that purport to treat anxiety. Most have a few small sketchy studies backing them up. Together, they form a big amorphous mass of claims that nobody has the patience to sift through or care about.
But recently silexan (derived from lavender) has started to stand out of the crowd. Daily Mail had an interview with psychiatry professor Hans-Peter Volz, who said that silexan should be first-line for anxiety, replacing things like SSRIs and Xanax. And a very reputable professional publication within psychiatry, The Carlat Report, published an article and a podcast touting silexan:
Not many treatments in psychiatry have a large effect size. There’s stimulants for ADHD, ketamine for depression . . . and now Silexan for generalized anxiety disorder.
And:
Most therapies do not have robust effects, but Silexan is an exception. Consider it in adults with generalized anxiety disorder.
What’s going on?
Silexan is a branded extract of lavender oil created by Wilmar Schwabe GmbH, a German pharma company. Nobody is sure about the mechanism of action, but it probably involves serotonin 1A receptors, the same receptors blocked by mediocre anti-anxiety medication buspirone and some of the newer antidepressants.
Studies claim it to be highly effective against anxiety conditions. Carlat Report offers us the following data (table layout is mine):
Before silexan, the anxiety landscape was:
- SSRIs, which work fine, but only about half of people respond to them and some people have intolerable side effects.
- Benzodiazepines, which work great, but are really addictive.
- Quetiapine, which makes people so sleepy that they forget to be anxious, plus has various bad long-term side effects.
…plus some other things with even worse cost/benefit ratio that people rarely used.
Now people are saying that silexan works even better than benzodiazepines, doesn’t cause addiction, and has no major side effects! If true, this would change the world. SSRIs changed the world, and they’re nowhere near as impressive as silexan claims to be.
2: Is there evidence that it works?
Silexan has four meta-analyses, all of which show strong effects. But here’s a Venn diagram of the studies included in each analysis:
Astral Codex Ten for more