Is it safe to take spirulina while pregnant or breastfeeding?

No one knows! It may say "spirulina" on the bottle but how do you know what's really in it? Why would you want to take this anyway? Don't believe all the crazy claims made by these supplement makers who are after your hard-earned money. Buy fresh fruits and veggies at your local grocery store or farmers market! and do you smoke? If so, stop!
Yes. Spirulina is a natural carb and its safe as long as it does not result in too much weigh gain.