Shark cartilage is one of the most popular supplements in the United States, with over 40 brand name products sold in 1995 alone. Primarily used for cancer, its use became popular in the 1980s after several poor-quality studies reported "miracle" cancer cures.
Research on the shark cartilage derivative product AE-941 has renewed interest in shark cartilage for cancer, eye disorders, skin disorders, and a range of inflammatory disorders. However, there is currently insufficient evidence to recommend for or against shark cartilage for any indication. AE-941 is marketed under different names for different conditions: Neovastat® is used for cancer, PsovascarT is used for skin conditions, Neoretna® is used for eye conditions, and Arthrovas® is used for joint conditions. The U.S. Food and Drug Administration (FDA) granted orphan drug status to this agent in 2002.
Commercial shark cartilage is primarily composed of chondroitin sulfate (a type of glycosaminoglycan), which is further broken down in the body into glucosamine and other end products. Although chondroitin and glucosamine have been extensively studied for arthritis, there is a lack of evidence supporting the use of unprocessed shark cartilage preparations for this condition. Shark cartilage also contains calcium. Manufacturers sometimes promote its use for calcium supplementation.
Shark cartilage supplements at common doses can cost as much as $700-1,000 per month.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Derivatives of shark cartilage, such as AE-941, have been shown to reduce inflammatory responses. It has been proposed that shark cartilage, as an agent that blocks new blood vessel growth, may have potency against inflammatory conditions. Chondroitin sulfate and glucosamine sulfate, components of shark cartilage, may be too low in shark cartilage preparations for clinical benefit. There is insufficient data on the use of shark cartilage for inflammatory joint diseases, such as arthritis.
Early evidence suggests that shark cartilage may improve or stabilize vision in people with an eye disease that leads to loss of vision. Well-designed studies are required.
There is insufficient research on the use of shark cartilage as a pain relieving agent. Although not well studied in humans, anti-inflammatory and pain relieving properties of shark cartilage have been demonstrated.
There is insufficient data on the use of shark cartilage in the treatment of inflammatory skin conditions. The application of a shark cartilage preparation (Neovastat®) resulted in the reduction of skin irritation on the forearms of people. Several studies have been undertaken in people with skin conditions. Although promising, larger studies for this indication are needed.
Promotion of new blood vessels is necessary for tumors to grow and spread. Enthusiasm about shark cartilage has stemmed from evidence of its properties that block new blood vessel growth and from several poor-quality studies of people with numerous types of cancer. However, several studies of shark cartilage lacked evidence of benefit in the treatment of cancer. In the United States, shark cartilage products cannot claim to cure cancer, and the U.S. Food and Drug Administration (FDA) has sent warning letters to companies not to promote products in this way. Without further evidence from well-designed human trials, it remains unclear if shark cartilage is of any benefit in cancer.
* Key to grades
A: Strong scientific evidence for this use B: Good scientific evidence for this use C: Unclear scientific evidence for this use D: Fair scientific evidence for this use (it may not work) F: Strong scientific evidence against this use (it likley does not work)
Tradition / Theory
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Allergic skin rashes, ankylosing spondylitis (spinal arthritis), anti-inflammatory, atherosclerosis (clogged arteries), bacterial infections, contact dermatitis, degenerative diseases (chronic), diabetic retinopathy (retina damage due to diabetes), diarrhea, fungal infections, glaucoma, immune system stimulant, intestinal disorders, Kaposi's sarcoma, kidney disease, kidney stones, lupus, nervous system disorders, osteoporosis, Reiter's syndrome (arthritis in response to infection), sarcoidosis (chronic lung disease), scar healing, Sjogren's syndrome (autoimmune disorder affecting the tear and saliva glands), skin rash, wound healing, wrinkle prevention.
Note: To maximize the absorption of doses taken by mouth, shark cartilage should be taken on an empty stomach. Acidic fruit juices (apple, grape, orange, tomato, cranberry) should be avoided for 15-30 minutes before and after dosing.
For arthritis, 0.2-2 grams per kilogram have been taken by mouth daily in 2-3 divided doses.
For cancer, 80-100 grams or 1-1.3 grams per kilogram of shark cartilage extract have been taken by mouth daily in 2-4 divided doses. Doses of AE-941 (Neovastat®) have been taken by mouth and ranged from 30-240 milliliters daily, 20 milligrams per kilogram twice daily, or 120 mililiters twice daily at the start of chemo-radiotherapy during human trials. Shark cartilage (as Benefin® powder mixture mixed in a chilled drink a half hour before meals) has been taken by mouth in 3-4 divided doses daily starting at 24g daily and titrated upwards to 96g daily for a duration ranging from more than one month to beyond three months. Doses of 15 grams or 0.5-1 grams per kilogram of shark cartilage daily has been prepared as an enema in 2-3 divided doses.
Doses of 0.2 to 2.0 grams per kilogram of body weight per day, taken by mouth in two to three divided doses, have been studied.
For Kaposi's sarcoma, 100 grams of shark cartilage has been taken by mouth daily. Two daily divided doses of 3,750 milligrams of shark cartilage has been taken by mouth and increased after three months to 4,500 milligrams in three daily divided doses.
For skin inflammatory conditions, doses of 0.4-0.5 grams per kilogram of shark cartilage have been taken by mouth daily for four weeks. When skin irritation improved, people reduced dosages to 0.2-0.3 grams per kilogram of shark cartilage taken by mouth daily for an additional four weeks. Creams applied to the skin with 5-30% shark cartilage are available and have been recommended by some practitioners for the treatment of skin inflammatory conditions alone or with shark cartilage taken by mouth for 4-6 weeks. Studies have used 5-10% preparations applied to the skin daily.
Children (under 18 years old)
Shark cartilage is not recommended in children due to a lack of scientific study and a theoretical risk of blocking blood vessel growth. There is one report of a nine year-old child with a brain tumor treated with shark cartilage who died four months later.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid with known allergy or sensitivity to shark cartilage or any of its ingredients, including chondroitin sulfate and glucosamine. Caution should also be used in people with a sulfur allergy since shark cartilage products may be sulfated.
Occupational asthma in workers exposed to shark cartilage powder or dust has been reported, including one death possibly related to sensitivity with lung complications in a 38 year-old male, although it is not clear if shark cartilage or underlying severe reactive airway disease was the cause.
Side Effects and Warnings
A limited amount of published research suggests that shark cartilage is well tolerated in most people at recommended doses. The most common side effects reported are mild-to-moderate stomach upset and nausea.
Shark cartilage is likely safe when taken in recommended doses for up to 18 months.
Shark cartilage may alter blood sugar levels. Caution is advised in people with diabetes and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.
Shark cartilage may cause low blood pressure. Caution is advised in people taking drugs or herbs and supplements that lower blood pressure.
Use cautiously in people with abnormal heart rhythms, heart conditions, kidney dysfunction, liver dysfunction, lung disorders, musculoskeletal disorders, stomach and intestinal disorders, and sulfur allergies.
Use cautiously in people receiving chemotherapy and those needing a troponin-I assay to test for decreased blood flow to the heart.
Avoid in people prior to surgery and after trauma.
Avoid with known allergy or sensitivity to shark cartilage or any of its ingredients, including chondroitin sulfate and glucosamine.
Avoid in pregnant or breastfeeding women and children.
Shark cartilage may cause abnormal heart rhythms, altered consciousness, bloating, blocked blood vessel growth, bone pain, cramping, decreased motor strength, decreased sensation, diarrhea, difficulty breathing, dizziness, generalized weakness, fatigue, increased levels of calcium, inhibit wound healing, liver inflammation, low levels of white blood cells, nausea, taste alteration, and upset stomach.
Pregnancy and Breastfeeding
Shark cartilage should be avoided in pregnant or breastfeeding women. Shark cartilage may block the growth of new blood vessels and drugs with similar properties, such as thalidomide, can cause birth defects. There is limited study of shark cartilage in these areas.
Shark cartilage may alter blood sugar levels. Caution is advised when using medications that may also alter blood sugar. People taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Shark cartilage may cause low blood pressure. Caution is advised in people taking agents that lower blood pressure
Shark cartilage may also interact with agents for arthritis, agents for the blood, agents for the heart, agents for the kidneys, agents for the stomach and intestines, agents that alter the immune system, agents that block new blood vessel growth, agents toxic to the liver, anesthetics, anticancer agents, anti-inflammatories, cisplatin, diuretics, heart rate regulating agents, interferons (? and ?), pain relievers, thalidomide, and thiazide.
Interactions with Herbs and Dietary Supplements
Shark cartilage may alter blood sugar levels. Caution is advised when using herbs or supplements that may also alter blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Shark cartilage may cause low blood pressure. Caution is advised in people taking agents that lower blood pressure
Shark cartilage may also interact with anesthetics, anticancer herbs and supplements, anti-inflammatories, antioxidants, calcium supplements, chondroitin sulfate, diuretics, glucosamine sulfate, heart rate regulating herbs and supplements, herbs and supplements for arthritis, herbs and supplements for the blood, herbs and supplements for the heart, herbs and supplements for the kidneys, herbs and supplements for the stomach and intestines, herbs and supplements that alter the immune system, herbs and supplements that block new blood vessel growth, herbs and supplements toxic to the liver, minerals, and pain relievers.
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The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.