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[159.112.244.27]) by mx.google.com with UTF8SMTPS id 6a1803df08f44-89c8533cac6si6185486d6.386.2026.03.19.12.02.47 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 Mar 2026 12:02:47 -0700 (PDT) Received-SPF: pass (google.com: domain of bounce+a6cce7.4d1858-tjphuhs=gmail.com@mg2.substack.com designates 159.112.244.27 as permitted sender) client-ip=159.112.244.27; Authentication-Results: mx.google.com; dkim=pass header.i=@mg2.substack.com header.s=mailo header.b=K3+3JIh6; dkim=pass header.i=@mailgun.org header.s=mg header.b=jQlIO+af; spf=pass (google.com: domain of bounce+a6cce7.4d1858-tjphuhs=gmail.com@mg2.substack.com designates 159.112.244.27 as permitted sender) smtp.mailfrom="bounce+a6cce7.4d1858-tjphuhs=gmail.com@mg2.substack.com"; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=substack.com DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg2.substack.com; q=dns/txt; s=mailo; t=1773946967; x=1773954167; h=List-Unsubscribe-Post: List-Unsubscribe: List-Post: List-Id: List-Archive: List-Owner: Reply-To: In-Reply-To: References: Sender: Sender: Date: Message-Id: To: To: From: From: Subject: Subject: Content-Type: Mime-Version: X-Feedback-Id; bh=5wSmOsQIE6R5zpzerfd0LWJGoRUqFQN0uBfou9s+Q6I=; b=K3+3JIh6DQEA+fh71bsey/uCDkHpI7rKC0LwwAZk7jggVuyOqo9gntoN0CyL6QFyQtunx9nEPEudBS/06CAstB8kk0eAF1HrPUHB8zrUbGThnujWT1qqJR0Y8sAqVhAzAGrkyfXM60vTyPokGIFnCaskNAvHstN/gbUISx6T57E= DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mailgun.org; q=dns/txt; s=mg; t=1773946967; x=1773954167; h=List-Unsubscribe-Post: List-Unsubscribe: List-Post: List-Id: List-Archive: List-Owner: Reply-To: In-Reply-To: References: Sender: Sender: Date: Message-Id: To: To: From: From: Subject: Subject: Content-Type: Mime-Version: X-Feedback-Id; bh=5wSmOsQIE6R5zpzerfd0LWJGoRUqFQN0uBfou9s+Q6I=; b=jQlIO+af7mdTL+UnKz3zAqJFuH5nCjm1/TEYGBy3dYFNM4O631Fsru+8aHE6lX/EA4PceHvWQqgh3WWDWao6C5sN1+CSlW8PQ9XKRInYcZppkzde1Si9aYLaGKHJu5pJuXSSP9qkDgXrHJD1D5fZGeP9oKsCcAadgmQ84LnYzRk= X-Mailgun-Sid: WyIxODZiYSIsInRqcGh1aHNAZ21haWwuY29tIiwiNGQxODU4Il0= X-Feedback-Id: postmaster@mg2.substack.com:post:5a78b6d5cd16820001f2a9d4:mailgun Received: by 5b9325f79c84707333ed249f64c215e64dad5fee75dd34862264bdd2443594e6 with HTTP id 69bc48579f0776df75262bcc; Thu, 19 Mar 2026 19:02:47 GMT X-Mailgun-Sending-Ip: 159.112.244.27 Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="92bba9fc152a01ff803f6a18b2a4456196cd84cfcb80a3bd2cf5292dc577" Subject: Tesamorelin Degradation Baseline vs Month 1 | Room Temp vs Refrigerated | Peptide Crafters From: Derek from Peptide Price To: tjphuhs@gmail.com X-Mailgun-Tag: post X-Mailgun-Track-Clicks: false Message-Id: <20260319190133.3.25a37174aebba8c5@mg2.substack.com> Date: Thu, 19 Mar 2026 19:01:33 +0000 Feedback-Id: post-191509485:cat-post:pub-3365367:substack Sender: Derek from Peptide Price References: In-Reply-To: Reply-To: Derek from Peptide Price List-Owner: List-Url: List-Archive: List-Id: List-Post: List-Unsubscribe: List-Unsubscribe-Post: List-Unsubscribe=One-Click X-Mailgun-Variables: {"category": "post", "email_generated_at": "1773946967013", "is_freemail": "true", "post_audience": "everyone", "post_id": "191509485", "post_type": "newsletter", "pub_community_enabled": "true", "publication_id": "3365367", "subdomain": "derekpruski", "user_id": "273622398"} --92bba9fc152a01ff803f6a18b2a4456196cd84cfcb80a3bd2cf5292dc577 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable View this post on the web at https://derekpruski.substack.com/p/tesamorelin= -degradation-baseline Earlier today I shared a sneak peek at the first month of Peptide Crafters= =E2=80=99 Tesamorelin degradation study. Shortly after they got back to me = with the baseline COA, so now we can do a proper comparison. Here=E2=80=99s= the full breakdown. Most people in this space know they should store their peptides properly bu= t have never actually seen data showing what happens when you don=E2=80=99t= =2E This study starts to answer that qu= estion with real numbers from a contro= lled comparison. Study Setup Same batch (PC-G2-TS10), three samples tested by Janoshik on February 16, 2= 026 to establish a starting point =E2=80=94 think of this as the =E2=80=9Cb= efore=E2=80=9D snapshot. Two months of additional testing still to come. Here=E2=80=99s how the timeline worked before that baseline test even happe= ned: the samples were produced, spent about a week in dry storage at the fa= cility, then shipped to Janoshik which took another week. So by the time Ja= noshik tested them for baseline, they had already been sitting in lyophiliz= ed (freeze-dried powder) form for roughly two weeks. Once baseline was conf= irmed, each sample was assigned to its storage condition and the clock star= ted. Storage conditions: Sample B =E2=80=94 room temperature at 68=E2=80=9370=C2=B0F Sample C =E2=80=94 frozen at -39=C2=B0F Sample A =E2=80=94 held for later timepoints in the study One thing worth flagging for context: most researchers store peptides in a = standard household fridge running around 35=E2=80=9340=C2=B0F. The =E2=80= =9Crefrigerated=E2=80=9D condition here is actually a freezer at -39=C2=B0F= , which is colder than what most people are working with at home. The real-= world difference between room temperature and a standard fridge may be a bi= t smaller than what this study shows =E2=80=94 but the direction of the res= ults will almost certainly be the same. Baseline =E2=80=94 February 16, 2026 Sample A =E2=80=94 10.76 mg | Purity: 99.894% Sample B =E2=80=94 11.46 mg | Purity: 99.876% Sample C =E2=80=94 10.90 mg | Purity: 99.861% All three samples started in essentially the same place =E2=80=94 purity ri= ght around 99.86=E2=80=9399.89%. That=E2=80=99s a clean, consistent startin= g point across the board. Month 1 Results =E2=80=94 March 16, 2026 Sample B (Room Temperature =E2=80=94 68=E2=80=9370=C2=B0F) Baseline: 11.46 mg | 99.876% Month 1: 10.81 mg | 98.184% Content loss: 0.65 mg (-5.67%) Purity loss: 1.692 percentage points Sample C (Frozen =E2=80=94 -39=C2=B0F) Baseline: 10.90 mg | 99.861% Month 1: 10.59 mg | 99.732% Content loss: 0.31 mg (-2.84%) Purity loss: 0.129 percentage points What The Numbers Actually Mean Think of purity as how much of what=E2=80=99s in the vial is actually the p= eptide you want versus broken down byproducts. The higher the number the be= tter. After one month in the freezer, Sample C dropped only 0.129 percentage poin= ts in purity and lost 0.31 mg of content. That=E2=80=99s essentially nothin= g =E2=80=94 the peptide is nearly identical to where it started. Sample B stored at room temperature is a different story. It lost 0.65 mg o= f content =E2=80=94 more than twice what the frozen sample lost =E2=80=94 a= nd dropped 1.692 percentage points in purity. That=E2=80=99s over 13 times = more purity degradation than the frozen sample over the exact same period f= rom the exact same batch. In plain terms: if your Tesamorelin sits at room temperature for a month, i= t is measurably less potent and less pure than when you started. Cold stora= ge largely prevents that. The narrative that refrigerating or freezing Tesamorelin causes degradation= has never had real data behind it. One month in, the frozen sample is sitt= ing at 99.732% purity with minimal content loss. That talking point should = be put to rest =E2=80=94 and two more months of data will make it even more= definitive. Where The Study Goes From Here This is month one of three. The real value here is the full progression =E2= =80=94 two more months of data will show whether the degradation rate stays= steady, speeds up, or levels off. Peptide degradation doesn=E2=80=99t alwa= ys move in a straight line, which is exactly why tracking it over multiple = months matters. If the gap between room temperature and frozen continues to widen through m= onths two and three, the cumulative difference is going to be substantial. = I=E2=80=99ll share the data as each round comes in. Big shoutout to Peptide Crafters for running this properly and letting me s= hare it with the community in real time. Unsubscribe https://substack.com/redirect/2/eyJlIjoiaHR0cHM6Ly9kZXJla3BydXN= raS5zdWJzdGFjay5jb20vYWN0aW9uL2Rpc2FibGVfZW1haWw_dG9rZW49ZXlKMWMyVnlYMmxrSW= pveU56TTJNakl6T1Rnc0luQnZjM1JmYVdRaU9qRTVNVFV3T1RRNE5Td2lhV0YwSWpveE56Y3pPV= FEyT1RZMkxDSmxlSEFpT2pFNE1EVTBPREk1TmpZc0ltbHpjeUk2SW5CMVlpMHpNelkxTXpZM0lp= d2ljM1ZpSWpvaVpHbHpZV0pzWlY5bGJXRnBiQ0o5LlVEeVg3cWxsMlRXOTlldFRDTlZTTU0yYjB= WRVNDaHVCaXZ5T2lFQ2xCUjgiLCJwIjoxOTE1MDk0ODUsInMiOjMzNjUzNjcsImYiOnRydWUsIn= UiOjI3MzYyMjM5OCwiaWF0IjoxNzczOTQ2OTY2LCJleHAiOjIwODk1MjI5NjYsImlzcyI6InB1Y= i0wIiwic3ViIjoibGluay1yZWRpcmVjdCJ9.9SrVadJLAX0LOk2YNWb2lDz-uPdl0QMLA5WLS0U= L4g4? --92bba9fc152a01ff803f6a18b2a4456196cd84cfcb80a3bd2cf5292dc577 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Tesamorelin Degradation = Baseline vs Month 1 | Room Temp vs Refrigerated | Peptide Crafters<= style> @media (max-width: 1024px) { .typography .pullquote-align-left, .typography.editor .pullquote-align-left, .typography .pullquote-align-right, .typography.editor .pullquote-align-right, .typography .pullquote-align-wide, .typography.editor .pullquote-align-wide, .typography .pullquote-align-center, .typography.editor .pullquote-align-center { float: none; 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Earlier today I shared a sneak peek at the first month of Peptide Craf= ters’ Tesamorelin degradation study.
͏     ­= 47;     ­͏     ­͏     = ­͏     ­͏     ­͏  =   ­͏     ­͏     ­T= 7;     ­͏     ­͏     &= #173;͏     ­͏     ­͏   =   ­͏     ­͏     ­͏= ;     ­͏     ­͏     &#= 173;͏     ­͏     ­͏   &= #8199; ­͏     ­͏     ­͏=     ­͏     ­͏     = 73;͏     ­͏     ­͏   &#= 8199; ­͏     ­͏     ­͏ =     ­͏     ­͏     = 3;͏     ­͏     ­͏   = 199; ­͏     ­͏     ­͏ &= nbsp;   ­͏     ­͏     ­= ;͏     ­͏     ­͏   Q= 99; ­͏     ­͏     ­͏ &n= bsp;   ­͏     ­͏     ­= ͏     ­͏     ­͏   ̳= 9; ­͏     ­͏     ­͏ &nb= sp;   ­͏     ­͏     ­&= #847;     ­͏     ­͏    = ; ­͏     ­͏     ­͏ &nbs= p;   ­͏     ­͏     ­&#= 847;     ­͏     ­͏    = ­͏     ­͏     ­͏  = ;   ­͏     ­͏     ­= 47;     ­͏     ­͏     = ­͏     ­͏     ­͏  =   ­͏     ­͏     ­T= 7;     ­͏     ­͏     &= #173;͏     ­͏     ­͏   =   ­͏     ­͏     ­͏= ;     ­͏     ­͏     &#= 173;͏     ­͏     ­͏   &= #8199; ­͏     ­͏     ­͏=     ­͏     ­͏     = 73;͏     ­͏     ­͏   &#= 8199; ­͏     ­͏     ­͏ =     ­͏     ­͏     = 3;͏     ­͏     ­͏   = 199; ­͏     ­͏     ­͏ &= nbsp;   ­͏     ­͏     ­= ;͏     ­͏     ­͏   Q= 99; ­͏     ­͏     ­͏ &n= bsp;   ­͏     ­͏     ­= ͏     ­͏     ­͏   ̳= 9; ­͏     ­͏     ­͏ &nb= sp;   ­͏     ­͏     ­&= #847;     ­͏     ­͏    = ; ­͏     ­͏     ­͏ &nbs= p;   ­͏     ­͏     ­&#= 847;     ­͏     ­͏    = ­͏     ­͏     ­͏  = ;   ­͏     ­͏     ­= 47;     ­͏     ­͏     = ­͏     ­͏     ­͏  =   ­͏     ­͏     ­T= 7;     ­͏     ­͏     &= #173;͏     ­͏     ­͏   =   ­͏     ­͏     ­͏= ;     ­͏     ­͏     &#= 173;͏     ­͏     ­͏   &= #8199; ­͏     ­͏     ­͏=     ­͏     ­͏     = 73;͏     ­͏     ­͏   &#= 8199; ­͏     ­͏     ­͏ =     ­͏     ­͏     = 3;͏     ­͏     ­͏   = 199; ­͏     ­͏     ­͏ &= nbsp;   ­͏     ­͏     ­= ;͏     ­͏     ­͏   Q= 99; ­͏     ­͏     ­͏ &n= bsp;   ­
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Tesamorelin Degradation Baseline vs Month 1 | Room Temp vs Refrigera= ted | Peptide Crafters

Derek
=
 
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READ IN APP3D""
 

Earlier today I shared a sne= ak peek at the first month of Peptide Crafters’ Tesamorelin degradati= on study. Shortly after they got back to me with the baseline COA, so now w= e can do a proper comparison. Here’s the full breakdown.

Study Setup

Same batch (PC-G2-TS10), three samples tested by Janoshik on February 16, = 2026 to establish a starting point — think of this as the “befo= re” snapshot. Two months of additional testing still to come.

Here’s how the timeline worked before that baseline test eve= n happened: the samples were produced, spent about a week in dry storage at= the facility, then shipped to Janoshik which took another week. So by the = time Janoshik tested them for baseline, they had already been sitting in ly= ophilized (freeze-dried powder) form for roughly two weeks. Once baseline w= as confirmed, each sample was assigned to its storage condition and the clo= ck started.

Storage conditions:

  • Sample B = — room temperature at 68–70°F

  • Sample C — frozen at -39°F

  • Sample A — held fo= r later timepoints in the study

One thing worth f= lagging for context: most researchers store peptides in a standard househol= d fridge running around 35–40°F. The “refrigerated” = condition here is actually a freezer at -39°F, which is colder than wh= at most people are working with at home. The real-world difference between = room temperature and a standard fridge may be a bit smaller than what this = study shows — but the direction of the results will almost certainly = be the same.

Baseline — February 16, 2026

  • Sample A — 10.76 mg | Purity: 99.894%

    • <= li style=3D"margin: 8px 0 0 32px;mso-special-format: bullet;">

    Sample B — 11.46 mg = | Purity: 99.876%

  • Sample C — 10.90 mg | Purity: 99.861%

<= a class=3D"image-link" target=3D"_blank" href=3D"https://substack.com/redir= ect/7f0f680e-df66-4cdc-8cfa-c4493d1b7f09?j=3DeyJ1IjoiNGl3b2U2In0.sVDxRtmZ85= v8kfdamY0krRXGMy3p768BWtuZifRB-Zs" rel=3D"" style=3D"position: relative;fle= x-direction: column;align-items: center;padding: 0;width: auto;height: auto= ;border: none;text-decoration: none;display: block;margin: 0;">3D"image.png"

All three samples started in essen= tially the same place — purity right around 99.86–99.89%. That&= #8217;s a clean, consistent starting point across the board.

Month 1 Results — March 16, 2026

Sa= mple B (Room Temperature — 68–70°F)

  • Base= line: 11.46 mg | 99.876%

  • Month 1: 10.81 mg | 98.184%

  • Content loss: 0.65 mg (-5.67%)

  • Purity loss: 1.692 percentage points

3D"image.png"

Sample C= (Frozen — -39°F)

    Baseline: 10.90 mg | 99.861%=

  • Month 1: 10.59 m= g | 99.732%

  • Conte= nt loss: 0.31 mg (-2.84%)

  • Purity loss: 0.129 percentage points

= 3D"image.png"

What The Numbers Actually Me= an

Think of purity as how much of what’s in = the vial is actually the peptide you want versus broken down byproducts. Th= e higher the number the better.

After one month in the free= zer, Sample C dropped only 0.129 percentage points in purity and lost 0.31 = mg of content. That’s essentially nothing — the peptide is near= ly identical to where it started.

Sample B stored at room t= emperature is a different story. It lost 0.65 mg of content — more th= an twice what the frozen sample lost — and dropped 1.692 percentage p= oints in purity. That’s over 13 times more purity degradation than th= e frozen sample over the exact same period from the exact same batch.

In plain terms: if your Tesamorelin sits at room temperature for= a month, it is measurably less potent and less pure than when you started.= Cold storage largely prevents that.

The narrative that ref= rigerating or freezing Tesamorelin causes degradation has never had real da= ta behind it. One month in, the frozen sample is sitting at 99.732% purity = with minimal content loss. That talking point should be put to rest —= and two more months of data will make it even more definitive.

Where The Study Goes From Here

This i= s month one of three. The real value here is the full progression — t= wo more months of data will show whether the degradation rate stays steady,= speeds up, or levels off. Peptide degradation doesn’t always move in= a straight line, which is exactly why tracking it over multiple months mat= ters.

If the gap between room temperature and frozen contin= ues to widen through months two and three, the cumulative difference is goi= ng to be substantial. I’ll share the data as each round comes in.

=

Big shoutout to Peptide Crafters for running this properly and= letting me share it with the community in real time.

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=

You're currently a free subscriber to Peptide Price. For the full exper= ience, upgrade your subscription.

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© 2026 Derek Pruski
548 Market Str= eet PMB 72296, San Francisco, CA 94104
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