The fax, which begins "Hi Laura, Just a quicky to let you know I am NOT pregnant after all. Phew!" was sent out by Planet Pharmaceuticals, which runs the website.
The fax goes on to talk in detail about how the signatory "Clare", has had sex with someone who was "lousy in bed" and speculates about the size of a significant body part of the person's brother, while promoting weight loss drug Reductil, Valium and sleeping tablets.
The ASA said: "We consider that the tone of the fax and content were likely to cause serious or widespread offence to recipients, most of whom seem to be small businesses.
"We were concerned that Medbargain was marketing prescription-only medicines to small business employees in their capacities as private individuals."
Some recipients were even on the Fax Preference Service suppression file. The fax was also sent to unsolicited recipients in circumstances prohibited by the Committee of Advertising Practice code.
The fact that the fax masqueraded as a private communication, and it was not clear who the advertiser was, was also an issue.
Planet Pharmaceuticals did not respond to initial ASA enquiries. It has now been asked by the ASA not to repeat the approach.
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