I have searched many online sources.

From one supplier I bought what I supposed to be a Thai product but I got once more glycine made in China (a quality certificate was added but it was based on the international Food Chemicals Codex of 1999 i.e. FCCIV)

Does any Forum member know where to buy glycine suitable as food supplement for humans?

Placbocine

Most of the bulk food additives here seem to be imported from China....

 

https://กรุงเทพเคมี.com/index.php?route=common/home

 

OR

 

https://www.tfac-shop.com/

 

Those are two sellers I'm familiar with in the BKK area.

 

You can buy bulk Glycine powder on Lazada.  I've bought some in the past.  But then again, I'm not freaked out that everything from China is somehow unfit for human consumption.  Western propaganda hammers out that everything China is "Bad," but at the end of the day, virtually all of the stuff Joe and Jane Average purchases in Walmart-Target-<add your Big Box Store here> are Chinese imports.

But, as they say here in Thailand, "Up to you!" 

If you somehow believe that your Glycine powder sold by Western retailers doesn't come from China like a vast majority of pharmaceuticals do?  Then try iHerb.com.   You'll pay a premium price for the same stuff, well, in my humble opinion.  I'm not anti-China.  The Western corporation off-shored manufacturing to China decades ago and destroyed Western domestic manufacturing.  The model holds true today as well. So if you think that what you buy from a Thai retailer who imports from China is somehow inferior? 
Well, I don't lay awake at night worrying about that.
Best of luck.

Thanks to TallGuyJohninBBK and to Connda

I lived and worked in China about 20 years ago and so I know there are manufacturers of excellent products and fake products which means we must verify what we buy.

Probably the most expensive food supplement is NMN and it is for 90% or more manufactured by Effepharm Shanghai (repacked and resold under other brand names mostly in the USA and UK) : this is an excellent product.

However about my question related to Glycerine with a certificate FCC IV my doubt was right and I copy hereunder the reply I got from a manufacturer in China : I need to by Pharmaceutical Grade and not FCCIV grade

QUOTE

Dear Ferdinand,

Good day to you.

Got your email forwarded by my colleague and checked with factory, the Glycine food grade is used in the food industry（mainly in seasoning application), and could meet FCC IV grade.

While If put it in food supplement, they need to use Glycine Pharmaceticual grade.

Regards,

UNQUOTE