Evidence: High Possible Benefits: Reasonable Safety: High
TABLE OF CONTENTS
What is collagen?
Collagen is a protein that can be obtained from food and supplements or produced in the body from proline, hydroxyproline, and glycine. It is most commonly sold as a supplement in the form of collagen peptides (also known as hydrolyzed collagen). Most people use it to improve skin and joint health. This article is about the main benefits of hydrolyzed collagen, its potential side effects, the best time to take it, and more.
What does collagen do for the body?
Collagen is needed for proper joint health, forming connective tissue, repairing skin damage and wounds, healing the gut lining, repairing joints, and more.
This protein can also break down into individual amino acids forming it. These are glycine, proline, and hydroxyproline.
Besides helping form collagen, each of these amino acids has its unique effects that can indirectly be supported by collagen supplementation.
For example, glycine acts as a precursor to a variety of molecules, such as creatine. Glycine can also act as a neurotransmitter with both stimulating and sedative effects. About 25% of collagen is made from this amino acid (by weight).
Possible benefits
The benefits mentioned below are dose-dependent. Generally, the higher the dose, the more pronounced the effects are. However, they do reach a plateau at a certain point. We will discuss the best dosing protocol later in this article.
Major benefits
Reduced joint pain – In healthy people with joint discomfort, supplemental collagen is somewhat effective at reducing joint pain during exercise. These people can also exercise longer without getting sore than the placebo group when taking the supplement. This benefit only occurs after 2-3 months of taking collagen but is persistent after. Research also shows a small benefit for osteoarthritis patients and a modest benefit for those with rheumatoid arthritis. About 10 grams seems to be an ideal dose in this regard.
Reduced symptoms of rheumatoid arthritis – Supplementation can reduce pain, swelling, stiffness, and tenderness caused by RA.
Minor benefits
Improved sleep quality – Multiple studies show that glycine supplements (about 3 grams taken an hour before bed) can increase sleep quality on the following night. 3 grams of glycine can be found in approximately 12 grams of collagen.
Improved cognition – This effect is secondary to improving sleep quality. In people who sleep well without the supplement and aren’t schizophrenics, glycine is unlikely to have a notable impact on cognition.
Reduced fatigue – This benefit is also secondary to improving sleep quality and doesn’t seem to apply to people who sleep just as well without supplemental glycine.
Reduced symptoms of schizophrenia – Glycine can reduce symptoms of schizophrenia when taken at extremely high doses (800+ mg/kg/d). This dose seems too impractical and may not be safe to take in the long term.
Improved insulin sensitivity – Low serum glycine levels are associated with insulin resistance. However, this is likely because insulin resistance leads to a depletion in glycine.
Reducing the negative effects of methionine – Glycine and methionine have to be kept in balance as too much of one (methionine, in particular) without enough of the other can cause unnecessary harm. For every gram of methionine, you need to consume at least half a gram of glycine if you wish to prevent side effects related to too much methionine. For optimal health, try to get about 1 gram of glycine for every gram of methionine.
Possible side effects
These side effects are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.
Nausea
Diarrhea
Increased oxalate levels – Doses of about 10 grams per day have been shown to increase oxalate levels in urine, likely because collagen consists of approximately 10% hydroxyproline, and a major metabolite of hydroxyproline is oxalate. As a result, higher doses of the supplement could increase the risk of oxalate-based kidney stones in susceptible individuals.
Amino acid imbalance – Essential and non-essential amino acids should be kept in balance as they act synergistically in many ways. Too much of one amino acid can sometimes cause side effects if there isn’t enough of another amino acid. For example, this principle applies to glycine and methionine, lysine and arginine, and the BCAA trio. There are many other proven and unproven examples. Food or a protein powder is usually a better choice for getting enough amino acids unless you have a specific goal in mind targeted by a particular amino acid/s.
Toxicity – While acute toxicity is extremely rare, taking high amounts of collagen could lead to chronic toxicity and cause some health problems. To prevent chronic toxicity, it is best to stay below 10 grams a day unless you have a great reason to take more.
Contamination – Contaminated supplements are uncommon in the USA and other well-regulated countries. However, if you wish to buy products from China, India, or other countries without strict regulations, beware that the supplements may be contaminated. Either way, you need to choose the brand you order from wisely. It is highly recommended to check the certificates or read through some reviews for the specific product before you buy it. The FDA (Food and Drug Administration) has the power to regulate dietary supplements but can only do so after they have been on the market for a while. That’s because supplement companies are not obligated to announce to the FDA when releasing a new product on the market. The FDA has to discover the product and test it for potential impurities, which can take a lot of time. During that time, the supplement can be sold on the market even if it’s impure. Also, supplement companies can change their manufacturers without announcing it to the FDA.
Who should not take collagen?
You should probably avoid taking the supplement if you:
get enough building blocks (mainly glycine, proline, and hydroxyproline) to make collagen endogenously
experience a severe adverse reaction after taking the supplement
are on a tight supplement budget (since there are more cost-effective supplements on the market for most people)
Who will benefit the most?
You should consider taking the supplement if you:
consume very little protein (less than 0.3 grams/pound of body weight)
take L-methionine (for optimal health, you should get at least half a gram of glycine for every gram of methionine)
are over 60 years old
have difficulty falling asleep (although pure glycine may be a better fit in this case)
eat high amounts of muscle meat
How much collagen should you take?
If you plan to take hydrolyzed collagen as a supplement, 5 grams appears to be the best daily dose for most people. This amount should provide most of the benefits without meaningful side effects.
Some people may benefit from doses higher than 5 grams. These include people who consume high amounts of muscle meat and those deficient in vitamin C.
The upper safety limit for collagen is not well-established. To stay on the safe side, don’t take more than 10 grams daily unless you have a great reason to do so. Higher amounts may cause problems if you take the supplement for a prolonged period.
Food sources of collagen
Collagen is mainly found in foods such as bone broth and sardines, where a person eats bones, joints, or the area close to them. With that said, most of the collagen we have in our bodies is synthesized endogenously.
The building blocks of collagen (glycine, proline, and hydroxyproline) are found in all whole foods containing dietary protein.
The amount of these amino acids per gram of protein varies from food to food but a general rule of thumb is that the more protein you eat, the more glycine you are getting from food.
Beware that for optimal health you should get at least half a gram (preferably a full gram) of glycine for every gram of methionine.
This is generally the ratio people get from their diet. However, people who eat lots of muscle meat (the richest source of methionine) without getting enough glycine can throw this ratio off balance. This can cause long-term negative effects on their health.
The easiest way to find out exactly how much glycine, methionine, or other amino acids you are getting from food is with Cronometer.com. This free app allows you to track all vitamins, minerals, and more.
Best time to take collagen
Hydrolyzed collagen is water-soluble, so you don’t have to take it with food to absorb it well.
To maximize the absorption, take collagen at least an hour before or after a meal so it doesn’t compete for absorption with other amino acids.
Whether you take the supplement in the morning or the evening doesn’t matter much. The supplement should not impact sleep quality in any negative way and may even increase sleep quality by getting broken down into glycine and other amino acids.
Unless it feels too impractical, spread the daily dose into 2+ smaller doses throughout the day.
Interactions
Methionine For every gram of methionine, you need to consume at least half a gram of glycine if you wish to prevent side effects related to too much methionine. For optimal health, try to get about 1 gram of glycine for every gram of methionine.
Other amino acids Essential and non-essential amino acids should be kept in balance as they act synergistically in many ways. Too much of one amino acid can sometimes cause side effects if there isn’t enough of another amino acid. For example, this principle applies to glycine and methionine, lysine and arginine, and the BCAA trio. There are many other proven and unproven examples. Food or a protein powder is usually a better choice for getting enough amino acids unless you have a specific goal in mind targeted by a particular amino acid/s.
Vitamin B3 Vitamin B3 supplements (such as niacinamide, nicotinic acid, NR, and NMN) can deplete levels of glycine in the body. If you’re taking nicotinic acid, combine it with half the dose of glycine to prevent liver toxicity. For example, for 1000 mg of nicotinic acid, take 500 mg of glycine. With the other forms of vitamin B3, you don’t need to worry about glycine as much.
Where to buy collagen
Amazon is the best option for ordering collagen supplements in most countries. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the internet.
Beware some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.
Collagen vs. gelatin
Collagen and gelatin supplements have virtually identical effects on the body.
The main difference lies in absorption. Collagen is more bioavailable and easier to absorb than gelatin.
FAQ
You can take the supplement daily and do not need to cycle it. However, it is certainly not a problem if you don’t take it daily. Not taking the supplement every once in a while could lead to better absorption. That is yet to be proven or disproven.
All of these options are fine. The two most important things to consider are the price and dosing. Powders are almost always the cheapest form. However, you may need a highly accurate scale to dose them correctly (preferably 0.001g). You can get one for as little as $20 from Amazon. Dosing the powders also takes some time that can add up over months or years. The disadvantage of capsules is that they often contain bovine gelatin, which rarely comes from an ethical source.
Yes. Collagen absorbs and digests well if you take it before falling asleep. The supplement should not impact sleep quality in any negative way and may even increase sleep quality by getting broken down into glycine and other amino acids.
This amino acid should not become harmful once it exceeds the expiration date but can lose potency over time.
Keep the supplement in a cold, dark, and dry place, and it should remain just as potent for many months or even years.
While toxicity is rare, too much collagen in the system can cause some health problems. It is best to stay below 10 grams a day to prevent these side effects.
You may need more of this amino acid if you: – eat very little protein (less than 0.3 grams/pound of body weight) – are deficient in vitamin C – have difficulty falling asleep (although pure glycine may be a better fit in this case) – eat high amounts of muscle meat – are deficient in glycine, proline, or hydroxyproline – suffer from rheumatoid arthritis – take L-methionine (for optimal health, you should get at least half a gram of glycine for every gram of methionine) – are over 60 years old
Most of the collagen in the body stays there for tens of years. Excess can be broken down into amino acids, such as glycine and proline.
If you are taking the supplement for improved joint health and reduced joint pain, you need to take it for about 2-3 months to begin noticing the benefits. If you take the supplement before bed to improve sleep quality, you may notice the benefits right after you wake up the next day.
Most collagen comes from animal gelatin but it can be synthesized from genetically modified yeast and bacteria as well. You can easily find vegan-friendly collagen pills and powders but always check the label to be sure. If you buy the supplement in a capsulated form, beware that the capsules often contain animal-based gelatin. Instead, find a brand that puts its products into cellulose capsules.
Collagen is mostly water-soluble, so you don’t have to take it with food to absorb it well.
Collagen should not break a fast unless you take a high dose at once. If you practice time-restricted eating, you can take this supplement during your eating window to make sure it doesn’t break your fast. Taking it on empty stomach may be slightly better if you wish to maximize the absorption.
References
Most of the information provided in this guide is supported by scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything said in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.
