I've been taking big (but not ridiculously huge) doses of B6 for PMS for years and years now. Last time I was buying it I couldn't find it and got B complex instead, which is a much lower dose, and I'm feeling the difference.
Neither Boots nor Superdrug had B6 in stock so I asked behind the Boots till and the assistant asked the pharmacist who said it was only available on prescription. Is this true at all? I couldn't find anything on Google.