The Complete Guide to Collagen

Your science backed guide to collagen benefits, dosage, marine vs bovine, and how to choose the right supplement for you.

Collagen supplements have grown in popularity in recent years as consumers look for natural ways to improve skin, hair, joint and overall health. But what is collagen, why do our bodies need it and what is the actual evidence behind the claims?

Understand the science behind collagen and feel empowered to make informed, realistic choices about your health and wellbeing

What does collagen do?

Collagen is a true multitasker when it comes to health and beauty. Supplementing regularly may help to:

Improve skin elasticity, hydration, and radiance
Reduce fine lines, wrinkles, cellulite, and stretch marks
Support stronger hair and nails
Protect bones and joints
Aid muscle repair and wound healing
Promote healthy blood sugar levels and calm gut inflammation
Encourage restful sleep and ease menopausal symptoms, such as hot flushes and mood swings

By replenishing collagen levels from within, you’re supporting your body’s structure, strength, and natural glow.

What is collagen?

Collagen is the most abundant protein in the human body, making up around 75% of our skin and about a third of our total body protein. It acts as the “scaffolding” that keeps skin firm, plump and smooth, while also supporting healthy joints, bones, hair and nails. Collagen supplements replenish the body's collagen levels from within to support the body's structure, strength and natural glow.

Is it better to take collagen in powder form?

We believe powder is the best way to take collagen. Some collagen is pre-mixed into ready-made liquids, but this process may reduce its effectiveness. Hydrolysed collagen peptides are very stable in dry powder form, which means mixing fresh ensures you get the full benefit of 10,000mg of marine collagen in every serving at its most potent and bioavailable.

Can men take collagen?

Yes, collagen is just as beneficial for men as it is for women. It supports skin, hair, nails, joints, muscles, and overall wellbeing for everyone.

Is it better to take collagen supplements in the morning or at nighttime?

It’s completely up to you; collagen works just as well at any time of day. Some of our customers enjoy taking Collagen Shots first thing in the morning as part of their wellness routine, while others prefer it in the evening. Whichever time you choose, you can be confident you’ll still see amazing results.

Can I take collagen supplements when pregnant or breastfeeding?

Collagen is a natural protein and may be helpful during pregnancy. However, we always recommend checking with your doctor or medical adviser before taking any supplement while pregnant or breastfeeding.

What is marine collagen?

Marine collagen is sourced from fish and is the most bioavailable form of collagen for the human body, meaning it’s absorbed quickly and effectively. Rich in type I collagen, it helps to support skin, hair, nails, and bones from within.

What's the difference between marine vs bovine collagen?

Marine collagen is derived from the scales or skin of fish and is rich in Type 1 collagen. Bovine collagen is most commonly farmed from cows and contains Type 1 and 3 collagen. Marine collagen is more bioavailable than bovine. Bovine collagen tends to have a thicker texture and mild smell compared to marine collagen. Learn more about the differences between marine and bovine collagen.

Signs you may have a collagen deficiency

Collagen proteins are essential structural building blocks for your body. But collagen levels reduce as we age, and your body may begin to show signs of low collagen.

What are the signs of collagen deficiency?

Does collagen help you sleep?

We all know the important role that sleep plays in our overall well-being, but some people struggle to get a good night's sleep. What do the studies show about collagen's impact on sleep?

Is collagen good for hair?

We normally think of collagen as just being in our skin, but did you know that collagen is in every strand of hair.

Is collagen good for joints?

Collagen isn’t only about glowing skin, it’s the primary structural protein in our joints, acting as the cushion, framework and shock absorber that keeps us moving freely. Over 60% of the cartilage that protects our joints is made of collagen.

Is more expensive collagen better?

Not always. The price on the pouch can be misleading. What matters is how much collagen you're actually getting per serving, whether the formula includes supporting ingredients, and the cost per gram when calculated fairly.

	Rejuvenated Collagen Shots Marine · 10,000mg	Absolute Collagen Marine · 8,000mg	Ancient + Brave Marine · 5,000mg
Cost per gram — the fairest comparison
Cost per gram (subscription)	14p/g Best value	25p/g	15p/g
Collagen dose
Collagen per serving	10,000mg	8,000mg	5,000mg
Meets 10g clinical dose?	✓ Yes	~ Close	✗ 2 servings needed
Added active ingredients
Total added actives	5	1	0

Prices correct as of June 2026. Per-gram calculations based on published pack prices and total collagen content. Competitor data sourced from brand websites and major UK retailers.

A lower pouch price doesn't always mean better value. Rejuvenated Collagen Shots deliver the full 10g clinical dose with 5 added active ingredients (hyaluronic acid, Vitamin C, açaí, B vitamins, copper & zinc) at just 14p per gram on subscription. See the full breakdown, including pack pricing and clinical credentials.

15 things to know about collagen protein

What is collagen protein? Collagen is the most abundant protein in the body, making up around 75% of skin and around 30% of total body protein.

Do collagen supplements work? 7 common questions

Collagen has quickly become a buzzword in the beauty and wellness world. but what exactly is it, and why is it so important?

Cellular health and how collagen supports it

Discover how collagen supports stronger, younger-acting cells and why this powerful extracellular protein is key to firmer, radiant, healthy-looking skin from within.

How much collagen should I take per day?

If you’ve ever wondered, “how much collagen should I take?” or“how many mg of collagen is right for women?”, you’re not alone. As collagen supplements continue to dominate the wellness space, understanding the optimal dosage is essential for seeing real results.

Can you take too much collagen? A complete guide to safe daily doses

If you’re taking a collagen supplement, you may be wondering: can you take too much collagen? The good news is that collagen is generally considered safe and well tolerated, with studies investigating doses far higher than those typically taken each day. In this guide, we’ll explore how much collagen is safe, potential side effects and whether it’s safe to take collagen every day.

How to get started with Collagen Shots

If you're new to taking Collagen Shots here are our top tips to get the best results when drinking your daily dose of goodness.

How long does collagen take to work?

Wondering how long it takes for collagen to make a visible difference? Whether you’re taking collagen for skin, hair, nails or joint health, results don’t happen overnight, but there is a timeline worth knowing. In this guide, we break down when you can expect to feel and see changes, explain what influences those results, and share expert tips to help you get the most from your collagen routine.

Can you take collagen during pregnancy?

Do you have questions about if you can take collagen during pregnancy? We have the answers for you here.

Is collagen good post workout?

Collagen is not just for beauty; it’s an essential ally for an active lifestyle.

Is there scientific proof that collagen supplements are effective?

Multiple peer-reviewed studies have shown that hydrolysed collagen peptides can improve skin elasticity, reduce fine lines, and support joint and connective tissue health. Rejuvenated's formulations use clinically studied doses to deliver these benefits.

View the results

Clinical studies of Collagen Shots

In a 2024 clinical study conducted by the GBA Polska Cosmetics Research Centre, Collagen Shots was tested over a 60-day period in women aged 35-55. The results? Both dermatological assessments and participant feedback confirmed visible and measurable improvements in skin health, adding clinical credibility to what our customers have been saying for years.

Discover the proof

Best Seller

Collagen Shots

The original collagen drink

10,000mg marine collagen per serving
30 servings (powder)
Gluten & lactose free

From as low as £42.00 / £1.40 per day

Probiotics Collagen Shots

For youthful, healthy skin

10,000mg marine collagen per serving
30 servings (powder)
Gluten & lactose free

From as low as £44.00 / £1.47 per day

Skin Perfecting Complex

Soothe & perfect skin

Vegan friendly
60 capsules
Gluten & lactose free

From as low as £19.96 / £0.67 per day

Meet Kathryn, the Founder of Rejuvenated

With over forty years' experience in the health and beauty industry, Kathryn Danzey is a firm believer in the power of collagen when it comes to your skin and overall wellbeing. Meet Kathryn, the Founder of Rejuvenated.

Our Story

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