I have bought a kitten wormer but people tell me its no good.

[OnEdge]

I bought the syrup by johnson and two people have told me its a waste of time. How can it be sold if this is the case ? Which kitten wormers are effective ?

Usually, if it can be sold over the counter then it won't be effective, as the nasty chemicals that really do the job you need a prescription for (same goes for flea and mite treatments).

These things can often still be sold as the active ingredient will kill worms in laboratory tests, but not necessarily in real-life situations due to dosing etc.

IIRC, Panacur paste is a pretty effective wormer for kittens. Best thing to do is ring some vets and ask what they would recommend.

As previously said anything sold over the counter are very very very old drugs so are much less effective. Also they are often paralyse and purge so you get diarrhoea.
There are several excellent new wormers on the market for kittens that are avaliable from the vets, many of whom offer a free kitten/ wormer check. In fact my surgery will check your kitten for free and give you the first two doses of wormer for free too - we are very nice .

Oh right, thanks a lot, I never knew all this, they shouldn't sell it