Yes, riboflavin is derived from hemp seed oil. hemp seed is the same substance that marijuana is.
No.
Yes, it can.
Certain medications, such as hydralazine, isoniazid, procainamide, and some anticonvulsant medications increase the chances of having a positive ANA test and biologic medications like Remicade, Humira, Enbrel can cause false positive results.
Prenatal vitamins will not cause a positive drug screen.
Diabetes alone will not cause a positive drug screen.
Zantac
Yes
YES! Search "phenylephrine and false positives"....you will get many websites listing many over the counter medications that can cause a positive drug screen. Phenylephrine, Dextromethorphan, & Guaifenesin...active ingredients in many cold remedies...will show positive for amphetamines
Smoking marijuana.
Absolutely it will.
permafry