Here is the FDA’s case against long-term use of thermogenic supplements and the references they used to support it:
FDA Proposed Rules: “The scientific literature establishes that use of ephedrine alkaloids for a period of several months or years can result in cardiomyopathy (Refs. 66 through 68).” [emphasis added]
66.) Van Mieghem W; Stevens E, and Cosemans J. “Ephedrine-induced cardiopathy.” Br Med J, 1978 Apr 1; Vol: 1; Number: 6116; Page: 816; PMID: 638463.
“He had exercise-induced and hyperventilation asthma since the age of 14. In 1958 he began to take a cough mixture containing ephedrine that relieved his bronchial spasms. He progressively increased his ephedrine intake, until he was drinking more than a bottle a day, each of which contained 400 mg of ephedrine. He was also taking liberal doses of prednisolone intermittently, depending on how he felt. In 1972 and 1973 he was treated in another hospital for cardiac failure but continued to take the cough mixture.” [emphasis added]
67.) To LB; Sangster JF; Rampling D, and Cammens I. “Ephedrine-induced cardiomyopathy.” Med J Aust, 1980 Jul 12; Vol: 2; Number: 1; Page: 35-6; PMID: 7432264.
“Fourteen months after her initial presentation, she was referred for psychiatric treatment by her general practitioner. Her husband had overheard a telephone conversation during which his wife revealed the financial burden imposed by her drug taking habits. His unexpected support and acceptance enabled her to seek help. It emerged that she had been taking large quantities of ephedrine-containing compounds for 10 years because these gain her energy and a feeling of well-being, and counteracted chronic fatigue and depression. She had originally taken Ephedrobarbital [ephedrine HCl & phenobarbital], but had changed to Tabasan, as this was more easily available. She had ingested 10 to 30 tablets of Tabasan daily [150–450 mg ephedrine HCl; 300–900 mg theobromine; 600–1800 mg salicylamide daily!] until the time of her admission to hospital for cardiac failure. She had not resumed taking Tabasan after discharge, but, three months later, she started taking increasing amounts of Phensedyl elixir. At the time of psychiatric referral, she was consuming three bottles (375 mL) daily [540 mg ephedrine; 270 mg promethazine HCl; 675 mg codeine phosphate daily!]” [emphasis and dosages added]
68.) Gaultieri J, and Harris C. “Dilated Cardiomyopathy in a Heavy Ephedrine Abuser.” Journal of Toxicology, Clinical Toxicology, 1996; Vol: 34; Page: 581-2 [Abstract, not on PubMed].
“We report a case of dilated cardiomyopathy in a heavy ephedrine abuser. Case: a 28 y [-year-old] 143 kg female presented with a 3 week history of progressing dyspnea, dry cough, fatigue, and orthopnea. She admitted to taking 25 mg ephedrine tablets for 8 y to lose weight but denied any other chronic drug or alcohol use except tobacco (1 ppd x 12 y) [1 pack per day x 12 years] . . . One week after the onset of her symptoms she reduced her daily intake from 80 tablets [2000 mg ephedrine!] to three tablets.” [emphasis and dosage added]
Let’s see, that’s 400 mg, 150–450 mg, 540 mg, and 2000 mg of ephedrine (the active part of the herb ephedra) daily, along with equally massive doses of prednisolone, phenobarbital, theobromine, salicylamide, promethazine, codeine, and nicotine. Is this the FDA’s “scientific evidence” that 10–25 mg doses of ephedrine t.i.d. or q.i.d. causes cardiomyopathy? I have never seen any medical expert or product label that recommended taking more than 100 mg/day of ephedrine, yet the FDA cites reports of people taking 4 to 20 times the recommended maximum dosage as evidence of its harmfulness! (The recommended maximum dosage of aspirin is 12 tablets per day. Try taking 48 to 240 aspirin tablets per day and see how quickly you present to the emergency room!)