FDA warns contract manufacturer over use of stimulant DMHA

The warning letter was addressed to NutraCap Labs​​, which is based in Norcross, GA.  The letter was unusually heavily redacted, presumably because some of the products cited belonged to brand holders.

In the letter the agency took the company to task for the inclusion of DMHA in at least one product. DMHA, or 2-amino-6-methylheptane, is a stimulant ingredient that goes by many names. Those include dimethylhexamine, 2-aminoisoheptane, 1,5-DMHA, 2-amino-6-methylheptane, 1,5- Dimethylhexylamine, 2-Isooctyl amine, and Octodrine. 

The ingredient was the subject of eight warning letters sent on the same day​​ in April 2019  by FDA to dietary supplement manufacturers.

DMHA started as drug ingredient 

According to a review paper published in the journal Brain Science,​ DMHA was originally developed as a nasal decongestant in the 1950s, but had not been on the market for many decades. It was revived in recent years by product formulators seeking new sources of stimulants in the wake of the banning of ephedra and DMAA. 

The authors noted a relative paucity of peer reviewed science on the ingredient. But what they were able to find featured a list of side effects that included mood swings, tremor, concentration deficiency, over-stimulation, energy crashes, anxiety, high blood pressure, dyspnoea, rapid heartbeat and heartburn​​ that were reported in the six to eight hours after ingestion. Other less frequent side effects include blepharospasm (twitching eyes), a rise in blood pressure and hyperthermia. 

Prominent industry critic Dr Pieter Cohen, MD, a frequent collaborator on peer reviewed papers outlining dodgy ingredients in the dietary supplement industry, was among the first to bring attention to the ingredient in a paper published in late 2017 in Clinical Toxicology​ ​in which some product seemed to be using DHMA and other chemically similar stimulants as stand-ins for DMAA, which by that time had been removed from the market by FDA. A paper published in 2018 by researchers from the University of Mississippi in the Journal of Pharmaceutical and Biomedical Analysis​​​ confirmed the presence of DMHA in some of the products tested. While some formulators claim various botanical sources for this ingredient, the Mississippi paper confirmed that the DHMA found in those supplements was of synthetic origin. 

Serving the start up market

NutraCap Labs is a contract manufacturer that concentrates on serving the market of dietary supplement startups that focus on online sales.  The company’s website features pages with titles such as “3 Types of Shopify Landing Pages”​ and “Top 10 e-commerce SMS templates to increase sales.”​

In addition to the DMHA citation, the warning letter also cited serious deficiencies in NutraCap Labs’documentation procedures. These included finished products which did not match the batch production records and shortcomings in the company’s use of master manufacturing records.

The warning letter also noted that NutraCap Labs did not perform adequate testing of incoming ingredients, preferring to rely on suppliers’ CofAs for things such as heavy metal levels.  The warning letter noted this does not comply with federal regulation, in that reliance on a supplier’s CofA can only be done if the supplier has been verified first, something that NutraCap Labs allegedly was not able to prove that it had done.

NutraCap Labs did not respond in time for publication for a request for comment.