I've just seen an advert promoting the "omega 3" in their product. Ignore anything that talks about "omega 3", they have no idea what they are talking about. The "essential oil" is omega-3, where the "-" means "minus". Unsaturated fatty acids have double bonds in the chain. The carbon atom next to the ester linkage is the alpha carbon, the second the beta. However many carbon atoms there are in the chain, the last one is the omega. Omega-3 means there's a double bond 3 carbons away from the end.
I've even seen puffs that suggest that omega-6 is twice as good as omega-3!