Do you know hamsters can fight to death even if they are a male and a female?

Did you know that there is also a risk of breeding? Is that what you want? To breed to have babies?

It is firstly a huge mistake to say you buy another so it can have a companion. Hamsters are not very social.... and they are only social in family groups if kept properly. WW do not die from loneliness, nor do they need a sex partner. The only way to solve is give 1 away or buy a new cage or tank for the other hamster.

Just for you to understand, Roborovskis are social and live in small groups, Winter white and russian campbell can live in groups or single. Groups would be family groups but it is risky coz will have inbreeding. Hamsters and most animals do not know the difference between mother and father, brother and sister. As long male and female they will mate and that would mean every 2 months have babies and the female will die early from over producing.
I normally tell people to buy 2 sisters or 2 brothers, never a male and female to avoid being cruel to them.

And if you buy 1, then keep only 1 coz it will have a hard time liking the other hamster. Big risk is death and injury from fights. And the other thing is stress.

Hamsters are better off alone, especially syrians.

Animals do not have feelings like humans. So do not think that just coz you feel lonely, the hamster would feel lonely.