Generally, collagen is considered a safe supplement and you will not have major side effects if you ingest too much.
The safe and effective amount
A safe but effective amount of collagen per day is between 12-15g. This also depends on your diet, age, and the reason you take collagen supplements.
If your daily diet contains a great number of citrus fruits, green vegetables, nuts, eggs, and whole grains that help your organism synthesize collagen, you should consider taking a lower amount of collagen supplement. Regarding your age, if you are in your early 20's you need fewer collagen amounts daily once your ''collagen-making mechanism'' works great. As the years pass by and you lose the ability to produce collagen, a higher amount of collagen is suggested.
You can ingest your collagen whenever you feel like it during the daytime or nighttime as some people noticed a better sleep quality when they started taking their supplement just before bed. If you have a sensitive stomach, it is better to consult your physician regarding your daily dose and time intake to have the best experience, but generally hydrolyzed collagen as it is easier to digest.
Sipnutri Liquid Diamond Collagen Drink is the best supplement to start off. It is a hydrolyzed marine liquid collagen supplement that provides you with 15g of collagen per bottle but also other nutrients such as vitamin C that are essential for your everyday function. It is a very convenient option as the suggested use is exactly one bottle so you can carry it around your work, gym, and trips(it is airport security friendly!). It has a fruity flavor so it won't make you feel ''forced'' to drink it and it won't leave a bad taste.
Liquid collagen can be a part of your daily meals or ingested between or after meals. You can use it as an addition to your favorite smoothies.