It seems that is what the
LHR rules are
You can take enough essential liquid, aerosol or gel medicines in your hand baggage to cover your journey plus a reasonable amount to cover any delays. Any liquid, aerosol or gel medication not needed on the flight, together with any spares must be packed in your hold baggage.
Makes no difference what the TSA does in the US. Many of us think the TSA rules are beyond ridiculous but we have to put up with them.
Contact details for LHR are on the website but you could contact the Civil Aviation Authority or the Department of Transport. But in all likelyhood you'll get a form reply from them too.