By Vlad Razumovich, Co-founder, QI Supplements
Published October 2026 | 5 minute read
Quick answer: what is Bonothyrk used for?
Bonothyrk is A-21, the parathyroid peptide bioregulator in Professor Vladimir Khavinson's range. It is a natural peptide complex from the parathyroid tissue of young animals, 10 mg per capsule.
Adults take it in 10 or 30 day courses. It may support the normal structure and function of the parathyroid glands and healthy calcium balance as part of a general wellness routine.*
It sits in the endocrine and metabolic support part of our health products. It is sold as a dietary supplement in capsules, hormone free and drug free. Some Khavinson peptides also come as sublingual preparations, but Bonothyrk A-21 is the capsule form. It is not parathyroid hormone, not teriparatide, and not a medical treatment.
Who it is for: healthy adults who eat a balanced diet and want a short course peptide for parathyroid health and general well being. It is not for children, or for any person who is pregnant or breastfeeding.
In this guide you will learn what you need before you order: what the glands do, how the product works, the best way to run a course, and what the research shows.
Shop Bonothyrk A-21 Parathyroid Peptide Bioregulator
What your parathyroid glands do
Most people have four parathyroid glands, each the size of a grain of rice, on the back of the thyroid. They keep calcium and phosphate in your blood inside a narrow range using one hormone, PTH.
PTH works in three places in the body (PMID 18160068). Bone helps as the calcium reserve. The kidneys decide how much calcium to keep and how much phosphate to let go. In the gut, PTH-activated vitamin D helps absorption of calcium from the food you eat.
Your nerves, muscles, heartbeat and brain need that balance at every stage of life. It is basic to a healthy life and long term health. If your calcium or PTH numbers are off, that is a case for your doctor, not a supplement.
How A-21 works: natural peptides and protein synthesis
Peptide bioregulators are short chains of amino acids taken from one tissue, each with a signature matched to that tissue. The theoretical mechanism: A-21 signals parathyroid tissue to support normal gland activity, and no other organ, a way of supporting normal cell activity in that tissue.*
The Khavinson system gives every organ a code. A-2 is thyroid, A-4 cartilage, A-17 adrenal, A-20 bone marrow, A-21 parathyroid. Our guide on how to read the Khavinson A-number system covers the code used across our peptide bioregulators.
The team at the St. Petersburg Institute of Bioregulation and Gerontology spent many years testing this. For example, a liver peptide raised protein synthesis in liver cells from rats aged 1 to 24 months, most in the oldest cells. A peptide for a different gland did nothing (PMID 15926314).
That study used liver peptides, not A-21. It shows the principle only.
Later work proposes the how. Ultrashort peptides enter cells through POT and LAT carriers (DOI 10.3390/ijms23147733). They may then reach DNA in the nucleus and bind DNA-specific sites on promoter gene segments, which is how natural peptides are thought to modulate gene activity specific to their tissue of origin (PMID 31808038, PMID 22708439).
So Bonothyrk is marketed as a geroprotective, healthy aging supplement. It is a Cytomax, a natural complex filtered from tissue. Lab built single sequence peptides are called Cytogens.
Bonothyrk vs other peptide preparations, calcium and PTH
|
Product |
What it is |
Its job |
|---|---|---|
|
Bonothyrk A-21 |
Parathyroid peptide complex |
Signal matched to parathyroid tissue* |
|
Bonomarlot A-20 |
Bone marrow peptide complex |
Different tissue and target |
|
Calcium, vitamin D3, K2 |
Minerals and vitamins |
Raw material and use |
|
PTH, teriparatide |
Prescription drugs |
Medical treatment |
One product does not stand in for another. For bone marrow, see our bone marrow health collection.
A mineral and a peptide preparation can share a routine without overlap. In addition, a balanced diet stays the base of mineral health and well being. No capsule will improve on poor food.
Bonothyrk dosage and course
The recommended adult dose is 2 capsules a day with meals, at the same time each day. Many people take one at breakfast and one at dinner.
The standard duration is 30 days, one 60 capsule pack. Then stop, and repeat every 4 to 6 months. A break between courses is part of the design and the way this guide recommends using it.
|
Pack |
Course |
Best for |
|---|---|---|
|
20 capsule pack, $55 |
10 days |
A first time try |
|
60 capsule pack, $135 |
30 days |
The recommended standard protocol |
Store each pack in a cool, dry place, out of reach of children. If you need several bioregulators, it helps to spread the courses across the year, not one week or month.
Add a pack to your cart and it ships from Washington State within 2 business days. Shipping is free over $50.
Key benefits of Bonothyrk, stated from the label
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10 mg of natural peptide complex A-21 per capsule
-
May support the normal structure and function of the parathyroid glands*
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May support healthy calcium and phosphate balance and normal bone density as part of a healthy life and general well being*
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Used in Khavinson musculoskeletal protocols built around normal, age related wear and tear*
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Based on 40+ years of research from the St. Petersburg Institute of Bioregulation and Gerontology*
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Short courses keep total cost and time low
You won't find promised results here. No published A-21 study backs guaranteed outcomes. When a page shows hard numbers, check which peptide was tested. And ask any seller whether the batch was made under GMP-certified conditions.
What to take Bonothyrk with
Khavinson protocols pair A-21 with Sigumir A-4, Vladonix A-6 and Ventfort A-3. That set is our Musculoskeletal System Bundle, from $180, a great option if you already plan to run Sigumir.
Some add Thyreogen A-2 for the thyroid. For the adrenal complex, read our Glandokort guide. Compare options in the parathyroid health collection or bone health collection.
What the research does and does not show
The mechanism and organ specificity work is peer reviewed. The gap is human data. I could not find a published human trial on A-21, so its effects in people have not been measured.
Treat it as an experimental peptide preparation. You are buying into a well studied principle, not a proven personal outcome. Use this guide as information for your health decisions, not medical advice.
Side effects, contraindications and safety
Bonothyrk has been sold for over 40 years with a good safety record. Anecdotal reports suggest peptide bioregulators have a low incidence of adverse effects.
Side effects have not been formally studied, and there is no published information on interactions with medicines.
-
It contains lactose and comes from animal tissue. Check the product label.
-
Sensitivity reactions are possible. If one happens, stop taking it and consult your doctor.
Contraindications: do not use it if you are pregnant, breastfeeding, under 18, or intolerant to any ingredient involved. Consult your doctor or a health professional before you get started if you take prescription medication, have osteoporosis or any calcium condition, or have other health problems.
Bonothyrk questions answered
Is Bonothyrk natural or synthetic?
Natural. It is a Cytomax filtered from parathyroid tissue.
How often should you repeat a course?
Every 4 to 6 months. It is not made for nonstop use.
Can men and women both take it?
Yes, adult women and men take the same serving.
Is Bonothyrk FDA approved?
No. The FDA does not approve dietary supplements the way it approves drugs. That is true of every supplement.
Ready to start? Add Bonothyrk A-21 to your cart, or save with the Musculoskeletal System Bundle. Questions? Feel free to ask our team before you order.
References: PMID 18160068; PMID 15926314; PMID 12374906; DOI 10.3390/ijms23147733; PMID 31808038; PMID 22708439.
About the author. Vlad Razumovich co-founded QI Supplements, selling Khavinson peptide bioregulators from Washington State since 2015. He holds a PMP certification and a Bachelor's degree from Kazan State University of Architecture and Engineering.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
