Both substances are used as precursors in the illicit production of methamphetamine, and to discourage that use the federal statute included the following requirements for merchants who sell these products:

A retrievable record of all purchases identifying the name and address of each party to be kept for two years
Required verification of proof of identity of all purchasers
Required protection and disclosure methods in the collection of personal information
Reports to the Attorney General of any suspicious payments or disappearances of the regulated products
Non-liquid dose form of regulated product may only be sold in unit-dose blister packs
Regulated products are to be sold behind the counter or in a locked cabinet in such a way as to restrict access
Daily sales of regulated products not to exceed 3.6 g to a single purchaser, without regard to the number of transactions
Monthly sales to a single purchaser not to exceed 9 g of pseudoephedrine base in regulated productsThe law gives similar regulations to mail-order purchases, except the monthly sales limit is 7.5 g.
As a pure herb or tea, má huáng, containing ephedrine, is still sold legally in the US. The law restricts/prohibits its being sold as a dietary supplement (pill) or as an ingredient/additive to other products, like diet pills. Australia
Ephedrine and all Ephedra species which contain it are considered Schedule 4 substances under the Poisons Standard (October 2015).
The most popular method for reducing ephedrine to methamphetamine is similar to the Birch reduction, in that it uses anhydrous ammonia and lithium metal in the reaction. The second-most popular method uses red phosphorus and iodine in the reaction with ephedrine. Moreover, ephedrine can be synthesized into methcathinone via simple oxidation. As such, ephedrine is listed as a table-I precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances. Detection of use
Ephedrine may be quantified in blood, plasma, or urine to monitor possible abuse by athletes, confirm a diagnosis of poisoning, or assist in a medicolegal death investigation. Many commercial immunoassay screening tests directed at the amphetamines cross-react appreciably with ephedrine, but chromatographic techniques can easily distinguish ephedrine from other phenethylamine derivatives. Blood or plasma ephedrine concentrations are typically in the 20–200 µg/L range in persons taking the drug therapeutically, 300–3000 µg/L in abusers or poisoned patients and 3–20 mg/L in cases of acute fatal overdosage. The current World Anti-Doping Agency (WADA) limit for ephedrine in an athletes urine is 10 µg/mL. Contraindications
Ephedrine should not be used in conjunction with certain antidepressants, namely norepinephrine-dopamine reuptake inhibitors (NDRIs), as this increases the risk of symptoms due to excessive serum levels of norepinephrine. Bupropion is an example of an antidepressant with an amphetamine-like structure similar to ephedrine, and it is an NDRI.