# Specific collagen peptides (Fortibone, Fortigel, Tendoforte, Verisol)

Branded collagen hydrolysates trialled for bone density, knee pain and tendons; safe, modest, slow.

- Page: https://peprank.xyz/peptides/specific-collagen-peptides
- Category: Recovery, joints & healing (Supplement)
- Also known as: Gelita bioactive collagen peptides; Fortibone (bone); Fortigel (cartilage / knees); Tendoforte (tendons and ligaments); Verisol (skin); in Healthy Bones Co., AlgaeCal Collagen, Designs for Health Whole Body Collagen, Momentous Collagen
- Routes: Oral
- Safety tier: Strict: Clean · Balanced: Clean · Evidence only: Clean
- Risk axes (0 none to 3 severe): Seen harm 0, Mechanism 0, Data gap 0, Silent harm 0, Product 1
- Positive: 51% of 25 graded reports glowing or positive, shrunk toward the 49% all-report average by 8 reports' weight
- Rank: #8 of 23 supplements
- Graded reports: 25 (Positive 13, Mixed 3, Nothing 6, Negative 2, Bad reaction 1)
- Evidence: Human RCTs — several mid-sized RCTs per product (bone n=131, knee pain n=180, skin n=114, tendon n=20-40), nearly all funded by or co-authored with the maker Gelita; no head-to-head trials against generic collagen
- Access: Supplement
- Onset: Joint and tendon effects judged at 8-12 weeks; bone density after 12 months; nails within 1-3 months.
- Lasts: Continuous use; users report aches returning within a week of stopping.
- Cost per month: ≈ €13–25 (at 2.5–5 g/day, iHerb at €0.17/g)
- Updated: 2026-10-30

## What users report

The liveliest reports come from r/osteoporosis: several women describe DEXA T-scores climbing (for example spine -2.2 to -1.4, -2.9 to -2.3) after 1-2 years of 5 g Fortibone, nearly always alongside weight training, HRT, calcium/D or drugs, so the collagen's share is unknowable. Others saw no DEXA change after a year. Joint and tendon users report less ache and a sense that pain returns when they stop. Faster nails and less hair shedding are a frequent side benefit. About a quarter notice nothing, and a few get stomach upset, a rash or histamine-type reactions, mostly with multi-ingredient blends. Tendon users following the gelatin/collagen plus vitamin C pre-loading protocol split between 'it worked for me' and 'did nothing'. Felt nothing: ~25% of reports.

**Effects:** bone density gains reported on DEXA (heavily confounded); less joint ache; pain returns when stopped; less activity-related knee pain (Fortigel); faster nails, less hair shedding, softer skin (Verisol); tendon support with loading rehab (Tendoforte / pre-exercise protocol)

**Downsides:** stomach upset in some; rash or histamine-type reaction with some blends; bovine taste/smell in some brands; costs 2-4 times generic collagen

**Caveat:** The brand distinction is largely industry-driven: Gelita funds or co-authors nearly all the trials, and none compares Fortibone or Fortigel with generic collagen at the same dose, so whether the 'specific' peptides beat cheap hydrolysate is unproven. Bone-density anecdotes come with weight training, HRT or drugs alongside. Collagen powders can carry trace heavy metals, so third-party-tested brands are preferable. Plain collagen is covered by its own entry.

**Typical use:** 5 g/day Fortibone or Fortigel, 5 g Tendoforte, or 2.5 g Verisol; for tendons, 10-15 g collagen or gelatin plus vitamin C 30-60 min before loading.

**Getting it:** Gelita sells only to brands, so products vary: Healthy Bones Co. and OsteoNaturals (Fortibone), AlgaeCal Collagen and Designs for Health Whole Body Collagen (Fortibone + Fortigel + Verisol), Momentous Collagen (5 g Fortigel + 10 g generic), Saltwrap and others (Tendoforte), Costco TruNature and Sparkle (Verisol).

**Stacked with:** vitamin C (with or before the dose) (needed for collagen synthesis; the pre-exercise protocol uses 50 mg+ vitamin C); loading exercise (every positive tendon and bone trial paired the peptides with training; 30-60 min before a tendon session); calcium, vitamin D, K2 (standard companions in the osteoporosis threads)

## Risk profile

- **Seen harm 0/3:** The Gelita RCTs (bone n=131 for 12 months, knee n=180, skin n=114) report no safety signal, and first-hand reports are stomach upset and a histamine reaction to a multi-ingredient blend, none serious.
- **Mechanism 0/3:** Bioactive collagen hydrolysates digested like dietary protein; no pathway to serious harm is known.
- **Data gap 0/3:** Hydrolysed collagen rests on gelatin's FDA 'no evidence of hazard' conclusion, and these brands add several mid-sized RCTs, nearly all funded by the maker.
- **Silent harm 0/3:** Reported harms (stomach upset, rash) appear within days and clear on stopping.
- **Product 1/3:** OTC supplements, but Gelita sells only to brands, so blends and doses vary, and collagen powders as a class carry trace heavy metals.
- **Never if:** Allergy to the source animal (bovine, porcine, fish)

## Top reports

- Positive, recovery, 10-20 g with vitamin C, 40 min before tendon exercise: “has helped me: try taking it with vitamin C, 10-20g 40 minutes before exercises that target the tendon.” — [r/fitness30plus](https://www.reddit.com/r/fitness30plus/comments/1dwmnhl/in_my_40s_i_find_my_tendons_let_me_down_are/lbw3p29/)
- Positive, longevity, 5 g Fortibone daily: “My spine improved from -2.9 to -2.3. So osteoporosis to osteopenia. One hip stayed the same and the other lost a little.” — [r/osteoporosis](https://www.reddit.com/r/osteoporosis/comments/1kfk2c1/collagen_with_fortibone_improving_anyones_dexa/n1b6meh/)
- Positive, skin-hair: “I also take Sparkle’s verisol collagen at the reco of Dr. MarieClaire and it has helped tremendously with cellulite.” — [r/Menopause](https://www.reddit.com/r/Menopause/comments/1ex3799/holy_that_worked_collagen_supplements_for_joint/lj5huyo/)
- Positive, skin-hair: “The outer changes that I've seen since starting are that my fingernails are gorgeous. They are long and strong and actually look good without polish. My hairline had started to recede a bit. I'm noticing a lot of hair growing back.” — [r/osteoporosis](https://www.reddit.com/r/osteoporosis/comments/1kbi4bs/collagen_peptides/)
- Positive, recovery, 15 g (10 g collagen + 5 g Fortigel): “I started with Momentous 15g Collagen about 8 weeks ago. It may all be in my head, but my shoulders feel pretty good, and I am adding weight consistently.” — [r/Supplements](https://www.reddit.com/r/Supplements/comments/1pcc1yc/collagen_for_joints_and_tendons/nrxh5c1/)

## Cheapest in Europe

- [Amazon.fr](https://www.amazon.fr/dp/B0FBRSNZCM/) (FR): Medicom collagen peptides with Verisol B, powder 150 g, €37, €0.25/g

## Studies

- [König et al., Specific collagen peptides improve bone mineral density in postmenopausal women (Nutrients 2018)](https://pubmed.ncbi.nlm.nih.gov/29337906/) (rct, n=131, 2018): 12 months of 5 g/day Fortibone raised spine and femoral-neck T-scores by about 0.1 vs no change or a slight fall on placebo; P1NP rose and CTX fell.
- [Zdzieblik et al., Specific bioactive collagen peptides in osteopenia and osteoporosis: 4-year follow-up (J Bone Metab 2021)](https://pmc.ncbi.nlm.nih.gov/articles/PMC8441532/) (open-label, n=31, 2021): Women who continued for 4 years kept gaining spine and femoral-neck BMD; uncontrolled.
- [Zdzieblik et al., Specific collagen peptides and knee joint discomfort in young active adults (Nutrients 2021)](https://pubmed.ncbi.nlm.nih.gov/33562729/) (rct, n=180, 2021): 12 weeks of 5 g/day cut exercise-related knee pain by 22 mm on a 100 mm scale vs 16 mm on placebo (p=0.024).
- [Praet et al., Tendoforte plus calf-strengthening in Achilles tendinopathy, pilot RCT (Nutrients 2019)](https://pubmed.ncbi.nlm.nih.gov/30609761/) (rct, n=20, 2019): Collagen peptides with a 6-month calf programme sped up VISA-A improvement compared with exercise plus placebo.
- [Jerger et al., Specific collagen peptides with resistance training and Achilles tendon properties (Scand J Med Sci Sports 2022)](https://pubmed.ncbi.nlm.nih.gov/35403756/) (rct, n=40, 2022): 14 weeks of training plus 5 g/day increased tendon cross-section by 11% vs 4.7% on placebo; stiffness and strength did not differ.
- [Proksch et al., Verisol reduces eye wrinkles and raises dermal procollagen (Skin Pharmacol Physiol 2014)](https://pubmed.ncbi.nlm.nih.gov/24401291/) (rct, n=114, 2014): 2.5 g/day for 8 weeks reduced eye-wrinkle volume by about 20% vs placebo, persisting 4 weeks after stopping.
- [Shaw et al., Vitamin C-enriched gelatin before intermittent activity augments collagen synthesis (Am J Clin Nutr 2017)](https://pubmed.ncbi.nlm.nih.gov/27852613/) (controlled, n=8, 2017): 15 g gelatin with vitamin C an hour before 6 minutes of rope-skipping doubled the blood collagen-synthesis marker; the basis of the pre-loading tendon protocol.

## Sources

- [Gelita: FORTIBONE product page and study list](https://www.gelita.com/en/products/collagen-peptides/fortibone)
- [Gelita: FORTIGEL product page and study list](https://www.gelita.com/en/products/collagen-peptides/fortigel)
- [Momentous Collagen Peptides label (10 g collagen + 5 g FORTIGEL)](https://www.livemomentous.com/products/collagen-peptides)