Have you heard of Thymosin Beta 4? Some people know it as TB4, or TB-500. In this video, I’m going to discuss this popular peptide, what it is, and its potential role in boosting the healing of orthopedic injuries, like ankle sprains, MCL and ACL injuries of the knee, Achilles tendon injuries, patellar and quadriceps tendon injuries, rotator cuff tendon injuries, muscle injuries and more.

Please understand, in this video, I am not giving you medical advice. This is meant for general information and educational purposes only.

I have gotten a lot of feedback and a lot of comments from readers and viewers over the last few weeks, talking about or asking about peptides. If you remember, I talked about the peptide BPC 157 on this show, and I’ve done a couple of videos on my website and YouTube channel about it. Many of those people have told me that they would like me to talk about other peptides and how they are used, what injuries they might be used for – that kind of thing. So that’s what I want to do today. We will discuss a very popular peptide – Thymosin Beta 4, or TB4, also called TB-500.

Let’s review what a peptide is.


Peptides are short chains of amino acids, or small proteins, so to speak, found naturally in our bodies. The one most people have heard of is insulin. Insulin is something our body naturally makes to handle the glucose that comes from our food. We make peptides naturally in our bodies. In fact, more than 7,000 naturally occurring peptides have been identified in our bodies.

Peptides are involved in almost every bodily action. They are signaling molecules, or communication signals. They are master controllers of functions throughout the body, including hormone production, cell signaling, and cell-to-cell communication. Each one has a specific role. The peptide binds to the receptor of a particular cell, causes that chemical reaction, and then goes away. Peptides have a very short half-life, so they are thought to be very safe. This is one of the key differences between peptides and hormones, like steroids, which stay around in your body a long time and cause all kinds of effects, both good and bad.

We naturally have high levels of these peptides as kids, and as young adults, but our levels decline with age. That is believed to be one of the reasons many tendon injuries occur more often in people in their forties and fifties than in teenagers and young adults.

Understand many of these peptides are still considered “experimental.” The FDA is currently “looking into the pharmacological assessment of peptides.” As of 2018, about 60 peptide drugs had been approved by FDA. Over 150 are in clinical development. Several hundred have been tested in clinical trials. More and more will come out as pharmaceutical drugs by the big drug companies in the coming years.

Thymosin Beta 4, or TB4, is a peptide.

And again, I am not giving you medical advice, and I’m not trying to influence you one way or another about whether peptides like Thymosin Beta 4 are right for you. I just want to help you understand them.


Thymosin Beta 4 is a peptide produced naturally in the thymus gland. It is a 43 amino acid sequence. It is found naturally in all of our cells, but studies have shown it exists in much higher concentration in areas of tissue damage.


TB4 has been shown to have what we call pleotrophic effects, meaning effects in multiple or different parts of the body. Most of the studies on Thymosin Beta 4 show its benefits for alcoholic liver injury and liver fibrosis, eye injuries and eye infections, peripheral neuropathies and strokes. It has even been shown to help with hair loss. It hasn’t been studied as much for orthopedic injuries like muscle injuries, tendon and ligament injuries, or osteoarthritis. But given how Thymosin Beta 4 works, it’s easy to see how it could help these types of injuries.


TB4 has been shown to help improve healing in a number of ways. It works at cellular level supporting tissue stem cells to heal and regenerate the injured tissue. It enhances collagen deposition. TB4 reactivates progenitor cells to repair damaged tissue. It promotes rapid wound healing with little to no scarring. And it is a potent anti-inflammatory for wounds, muscles, joints, reducing acute/chronic pain.

At a cellular level, TB4 up-regulates cell building proteins such as actin, a protein that with myosin in muscle cells, forms the contractile filaments. The up-regulation of actin allows TB4 to promote healing, cell growth, cell migration and cell proliferation.

And one of the great features of Thymosin Beta 4 is that it travels to the site of injury, which is probably why you see it in higher quantities in areas of tissue damage.


Again, there isn’t a lot of research on TB4 for muscle, tendon and ligament injuries, but several peptide experts believe that it might be very helpful for muscle injuries like hamstring, calf, and quadriceps injuries. Or tendon injuries like tennis elbow, Achilles tendinitis or tendinopathy and rotator cuff injuries.

It has been shown to prevent adhesion and fibrous band formation in injured muscles, tendons, and ligaments. These tissues heal with fibers haphazardly aligned, much like the game pick up sticks. In theory, Thymosin Beta 4 might help muscles, tendons or ligaments heal more quickly and with better alignment of the collagen and fibers to get back to normal strength and function quicker.

TB4 is usually administered as a subcutaneous injection.


As for how to take it, Thymosin Beta 4 is usually administered as an injection the patient gives himself or herself. There are oral forms of TB4 or TB-500, but there is debate about how bioavailable TB4 is when taken as a pill.


Also, it is really important to consider that if you want to try a peptide like Thymosin Beta 4, you need to get it from your doctor and not these online sites that sell peptides “for research purposes only.” That’s a really dangerous idea because you just don’t know what you’re getting. The websites look legitimate, and they make all kinds of safety claims. But these companies are not inspected by the FDA. In addition to the possibility that there will be little if any peptide actually in the vial or bottle sent to you, they often contain contaminants and endotoxins that can make people really sick. I’ve heard reports of people getting liver damage from using peptides they bought online.

Remember, most peptides, like Thymosin Beta 4, are not approved by the FDA and are not considered standard of care for most injuries and diseases. And I am not giving you medical advice, and I’m not trying to influence you one way or another about whether peptides like Thymosin Beta 4 are right for you. I want you to understand them better and consider talking to your doctor about them.

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See me as a patient

If you have a tendon or ligament injury and you want to see someone who truly knows about bone and joint injuries in athletes and active people, I’d be happy to help. I’m a double-board certified orthopedic surgeon and sports medicine specialist. I’d love to talk to you about all your options to recover from injury, not just surgery, cortisone shots, and physical therapy. Go to the Contact page to make an appointment to see me. The link to my website and the Contact information is in the description below this video.

I’m Dr. David Geier. Thank you for watching, and I look forward to helping you feel and perform Better Than Ever.