I am thinking to start consume collagen. But i have no idea how many mg of collagen is appropriate in a day. advice please

0.5 mg of collagen per day help in soft tissue health.

0.5mg? seriously? i'm eating a biscuit which contains 300mg in a small packet. 

Sorry typo from the phone, you'll need 5000mg a day.

Collagen doesn't work when eaten. Digested.

These 3 things cannot be eaten = glutathione, collagen, placenta

mind to further elaborate?
then why got so many products selling collagent drink? hmm

The three major classes of nutrients that undergo digestion are proteins, lipids (fats) and carbohydrates:
Proteins are degraded into small peptides and amino acids before absorption.[5] Chemical breakdown begins in the stomach and continues in the large intestine. Proteolytic enzymes, including trypsin and chymotrypsin, are secreted by the pancreas and cleave proteins into smaller peptides. Carboxypeptidase, which is a pancreatic brush border enzyme, splits one amino acid at a time. Aminopeptidase and dipeptidase free the end amino acid products.
Lipids (fats) are degraded into fatty acids and glycerol. Pancreatic lipase breaks down triglycerides into free fatty acids and monoglycerides. Pancreatic lipase works with the help of the salts from the bile secreted by the liver and the gall bladder. Bile salts attach to triglycerides to help emulsify them, which aids access by pancreatic lipase. This occurs because the lipase is water-soluble but the fatty triglycerides are hydrophobic and tend to orient towards each other and away from the watery intestinal surroundings. The bile salts are the "main man" that holds the triglycerides in the watery surroundings until the lipase can break them into the smaller components that are able to enter the villi for absorption.
Some carbohydrates are degraded into simple sugars, or monosaccharides (e.g., glucose). Pancreatic amylase breaks down some carbohydrates (notably starch) into oligosaccharides. Other carbohydrates pass undigested into the large intestine and further handling by intestinal bacteria. Brush border enzymes take over from there. The most important brush border enzymes are dextrinase and glucoamylase which further break down oligosaccharides. Other brush border enzymes are maltase, sucrase and lactase. Lactase is absent in most adult humans and for them lactose, like most poly-saccharides, are not digested in the small intestine. Some carbohydrates, such as cellulose, are not digested at all, despite being made of multiple glucose units. This is because the cellulose is made out of beta-glucose, making the inter-monosaccharidal bindings different from the ones present in starch, which consists of alpha-glucose. Humans lack the enzyme for splitting the beta-glucose-bonds, something reserved for herbivores and bacteria from the large intestine.

Collagen doesn't work when eaten. Digested.

These 3 things cannot be eaten = glutathione, collagen, placenta

And that is why you must not take your supplements after a meal, or right before meal time.
They get digested and is wasted. Collagen need to be absorbed. Please do some readings on the internet.
Best if injected, but that is a bit more expensive.

I am injection kaki. 

vit C + glutathione + alpha lipoic acid + kojic acid = week 1
placenta = week 2
rinse and repeat

on and off
botox & fillers

 

wow! You must have young and healthy look skin. 
But... are you a guy?

Yup. Nolah. Me pimple prone - with all the jabbing now more like a normal person nia...

Pic as in avatar.

I can see you are a sport elite. Bet you dont need those beauty injection and still look great! *jealous*

I am injection kaki. 

vit C + glutathione + alpha lipoic acid + kojic acid = week 1
placenta = week 2
rinse and repeat

on and off
botox & fillers

 

I am thinking to start consume collagen. But i have no idea how many mg of collagen is appropriate in a day. advice please