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Amino acid isomer confusion cleared up

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Not sure if this should be in the pharmacology forum, but we've had several posts on amino acid supplementation- especially tyrosine and tryptophan, so I'll put it here and see how it flies

A FOAF was concerned about purchasing amino acid supplements which didn't list the isomer on them, as such a description ( Tyrosine instead of l-tyrosine, Tryptophan instead of l-tryptophan etc ) implied that chemically the commercial products were a racemix of inactive d- isomers and active l-isomers and therefore only half as potent as was generally supposed.

On several supplier's websites the blurb for those aminos detailed the l-isomers as being active, but didn't mention the isomer/ racemix in the ingredients- so no clarification there.

They wrote to one manufacturers for clarification and received the following in reply:

The capsules contain 500mg of L-Tyrosine, plus standard encapsulating aids. However, in the application to the Therapeutic Goods Administration, the active ingredient (L-Tyrosine) must be stated using the Australian Approved Name (AAN) which is "Tyrosine BP"

This material as shown below in 'Product Overview'

Product Overview:

l-Tyrosine, USP, BP, EP, (BPC)

(S)-a-Amino-3--(4-hydroxyphenyl)propanoic acid Non-animal

The Therapeutic Goods labelling order, (TGO69) requires that the label must state the ingredient using the Australian Approved Name (without the pharmacopoeial reference - 'BP') which for this product is "Tyrosine' and does not permit referencing its laevo isomeric form name.

I'm sorry if this appears confusing - especially where a lot of published material specifies the particular isomer. However we must comply with labelling and other orders in order to maintain our Listing for this and other products in Australia. The dextro isomer of Tyrosine is not permitted in Listable medicines in Australia, and this is generally true of other amino acids where one of the isomers is inactive.

Very helpful, and cleared it up immediately

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hmmmm, this is dodgy. Phenylalanine come sin D & L, both for human therapeutic use. In fact most of it comes in DL. However, for anyone with anxiety disorder the D form can be quite detrimental as it form some compound that has a long adrenaline like action (sorry forgotten the compound but can look it up). The L form does not cause this and is much safer for people with high adrenaline type disorders.

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I was going to ask about the difference between the isomers and "Tryptophan" because I asked all three chemists here for tryptophan a few weeks ago and was told by the one chemist that actually knew what it was that they are all the same thing!

They also said that it was banned in NSW but not Qld???

So which 'type' is more suitable in my case T?

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I was going to ask about the difference between the isomers and "Tryptophan" because I asked all three chemists here for tryptophan a few weeks ago and was told by the one chemist that actually knew what it was that they are all the same thing!

:rolleyes: like most d-aminoacids d-tryptophan is not assimilated in the human body. If you take d-tryptophan you might keep some of your gut bacteria/fungy happy, but not yourself.

They also said that it was banned in NSW but not Qld???

That would be 5HTP, not TP. TP is legal in all states as long as it is in dosages of under 100mg per day. Golden Glow stocks it.

So which 'type' is more suitable in my case T?

L-tryptophan. And luckily you would probably not find anything else on any consumer catalog.

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btw, Bullivants has ceased distribution of the Nature's Own tryptophan, so now the only chemists that stock it are those who compound themselves.

Just for an idea of the timeline:

1986 - tryptophan available from all healthfood shops as Natures Own 500mg x60 for $8

1990 - no tryptophan due to manufacturing disaster and deaths.

1992 - tryptophan available by prescription from Bullivants. same pack $15

1994 - tryptophan available by prescription from chemists only (sourcing it from Bullivants). same pack $35

2000 - tryptophan available by prescription from chemists only (sourcing it from Bullivants). same pack $45

2005 - Bullivants ceases distribution. available from compounding chemists only. '00' caps containing 350mg x50 at $45

That last step almost doubles the cost. Mind you, tryptophan costs RETAIL about $700 per kilo (USP,BP), which brings the cost to $12. However, pharma cos would be able to source it at a fraction of this in bulk, making the cost probably no more than $5 inclusive of packaging and distribution.

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Taa for that....I didn't think they knew what they were on about ;)

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I've just searched the golden glow sight and can't find any tryptophan :(

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Product #1253 appears to be discontinued. That sucks.

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C'est la vie T ;)

But I did speak to a specialist there who recommended www.lef.org and said that they pour back all of their profits into their research into these supplements which is a good thing.

She also recommended somewhere up your way called phytofoods.They apparently sell a powdered form if you can get a health food store to order it.

ATM I'm going to sprout some wheatgrass and try that AFAIK there's no gluten in the the sprouts, only in the seeds.

sorry for diverting the thread but you're right it sux that it's so difficult to obtain these things in OZ particularly when you know that they work and I can't afford to order from O/S atm.

Much thanks.

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There are plenty of suppliers overseas, but unless they produce a discrete dosage unit of

Europe now has a limit of 220mg/day, so most pills from there won't be permitted in Oz either. It's a crappy situation.

http://www.vita-fit.co.nz/custom.htm

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Looks like it's gunna be a diet of sheep brains and wheat-grass then ;)

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