7 Signs Your Body Is Low in Collagen (And How to Fix It)

Collagen is the most abundant protein in your body — it makes up roughly 30% of total protein content and forms the structural foundation of your skin, joints, bones, tendons, and gut lining. Starting in your mid-20s, your body produces approximately 1% less collagen per year. By your 40s, you may have lost 20–30% of your collagen production capacity.

The signs of declining collagen show up in predictable, recognizable ways. Here are seven of the most common indicators — and what you can do about them.

1. Skin Losing Elasticity and Developing Fine Lines

Collagen gives skin its firmness and snap. As levels decline, skin loses its ability to bounce back — a quality scientists measure as "elasticity." The first visible sign is typically fine lines around the eyes (crow's feet), forehead, and mouth. As collagen loss accelerates, deeper wrinkles and sagging along the jawline and neck become more pronounced.

The research is robust: clinical studies consistently show that daily collagen supplementation improves skin elasticity and reduces wrinkle depth within 4–12 weeks. Read the science behind collagen's skin benefits.

2. Stiff or Achy Joints

Cartilage — the smooth tissue cushioning your joints — is made almost entirely of collagen, primarily type II. As collagen levels fall, cartilage thins and joint surfaces become less protected, leading to stiffness (especially in the morning), clicking sensations, and aching during or after activity.

This is one of the most clinically studied benefits of collagen supplementation. Research on collagen and osteoarthritis shows that 10g of collagen daily for 12 weeks significantly reduces joint pain and improves function in people with knee osteoarthritis.

3. Slow-Healing Wounds or Injuries

Collagen is central to the wound-healing cascade. When you cut yourself or strain a tendon, collagen synthesis fills in the damaged tissue. If minor injuries take longer to heal, bruises linger, or skin cuts seem slow to close, declining collagen production may be a contributing factor — especially common after age 40.

4. Hair Thinning or Increased Breakage

Collagen surrounds the hair follicle and provides structural support for healthy hair growth. While hair loss has many causes, collagen depletion contributes to weakened follicles, reduced hair shaft diameter, and increased breakage. The amino acids in collagen — glycine and proline — are precursors to keratin, the protein hair is made of.

Many people taking collagen primarily for skin notice improved hair thickness as a secondary benefit. Read more about how much collagen for hair growth.

5. Brittle Nails That Split or Peel

Nails that crack, peel, or break easily are among the earliest and most obvious signs of collagen decline. Nail keratin production depends on the same amino acid building blocks as collagen, and nails tend to respond fastest to supplementation — many people notice meaningful improvement in nail strength within 2–4 weeks.

6. Digestive Issues and Gut Sensitivity

Collagen — specifically the amino acids glycine and glutamine — plays a critical role in maintaining the integrity of the gut lining. When the gut lining weakens, undigested particles can pass through, triggering inflammation, bloating, food sensitivities, and fatigue.

Glycine makes up about one-third of collagen's amino acid composition and is one of the most studied gut-protective nutrients. Supplementing with collagen provides a concentrated source of glycine that helps repair and reinforce the intestinal barrier — a benefit you won't get from standard protein powders.

7. Loss of Bone Density

Bones aren't just calcium — they're a mineral-rich collagen matrix. Approximately 90% of organic bone mass is collagen type I. As collagen production declines, the scaffolding on which bone minerals are deposited weakens, contributing to reduced bone density and increased fracture risk. This is particularly relevant for postmenopausal women, who experience accelerated bone loss alongside hormonal collagen decline. Read our guide on collagen and menopause.

What to Do About Low Collagen

Supplement daily with hydrolyzed collagen peptides

10 grams per day is the dose used in most clinical research. Hydrolyzed collagen peptides are efficiently absorbed and delivered to collagen-producing cells throughout the body. Consistency matters — collagen works cumulatively, and results compound over weeks and months of daily use.

Include vitamin C in your diet

Vitamin C is a required cofactor for collagen synthesis. Without it, your body cannot convert proline to hydroxyproline, blocking collagen fiber formation entirely. Citrus fruits, bell peppers, kiwi, and strawberries are excellent sources. Taking collagen alongside a vitamin C-rich meal can meaningfully improve results.

Reduce collagen destroyers

UV exposure, smoking, high-sugar diets, and chronic stress all accelerate collagen breakdown. Broad-spectrum SPF, not smoking, and limiting refined carbohydrates protect your existing collagen reserves. Read more about protecting your body's collagen production.

Choose a tested, quality collagen source

Not all collagen supplements are equal. Look for hydrolyzed collagen peptides that are independently verified for purity. A product that is OU Kosher certified and independently 3rd party tested for heavy metals gives you the highest confidence in what you're consuming.

Address the Signs Before They Get Worse