Drug & supplement interaction

Branched-chain Amino Acids (bcaa) + Insulin Aspart

Insulin Aspart brand name: Fiasp.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Branched-chain Amino Acids (bcaa) has a moderate interaction with Insulin Aspart. Theoretically, BCAAs might alter the effects of antidiabetes medications.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceB
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Branched-chain Amino Acids (bcaa) and Insulin Aspart

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIDIABETES DRUGS

Why this applies to Insulin Aspart

Insulin Aspart falls under ANTIDIABETES DRUGS — the group Branched-chain Amino Acids (bcaa) interacts with.

Theoretically, BCAAs might alter the effects of antidiabetes medications.
Some evidence suggests that BCAAs might stimulate insulin release. However, a small clinical study in adults with liver cirrhosis and high nocturnal levels of blood glucose suggests that BCAAs might increase blood glucose levels.
Severity Moderate Likelihood Probable Evidence B

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing with BCAAs and your mealtime insulin (Fiasp). This isn't about your liver breaking the insulin down differently. Instead, BCAAs may nudge your blood sugar in a couple of directions. Some research suggests they can trigger a little extra insulin release, while one small study in people with liver cirrhosis found BCAAs actually pushed blood sugar up. So the effect can swing either way, which makes your numbers a bit less predictable.

Because you're already dosing insulin to match your blood sugar, that unpredictability is what matters most. Watch for signs of a low (shakiness, sweating, confusion) or a stubborn high. The evidence here is fairly weak and mostly theoretical, so I wouldn't panic. Just keep checking your levels and mention the BCAAs to your doctor or pharmacist before starting them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hutson SM, Harris RA. Introduction. Symposium: Leucine as a nutritional signal. J Nutr 2001;131:839S-40S.
  2. Kimball SR, Jefferson LS. Control of protein synthesis by amino acid availability. Curr Opin Clin Nutr Metab Care 2002;5:63-7.. PubMed
  3. Anthony JC, Lang CH, Crozier SJ, et al. Contribution of insulin to the translational control of protein synthesis in skeletal muscle by leucine. Am J Physiol Endocrinol Metab 282:E1092-101.. PubMed
  4. Kimball SR, Farrell PA, Jefferson LS. Invited review: Role of insulin in translational control of protein synthesis in skeletal muscle by amino acids or excercise. J Appl Physiol 2002;93:1168-80..
  5. van Loon LJ, Kruijshoop M, Menheere PP, et al. Amino acid ingestion strongly enhances insulin secretion in patients with long-term type 2 diabetes. Diabetes Care 2003;26:625-30. PubMed
  6. Nakanishi K, Namisaki T, Mashitani T, et al. Late-evening snack with branched-chain amino acid-enriched nutrients does not always inhibit overt diabetes in patients with cirrhosis: A pilot study. Nutrients. 2019;11(9):2140. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Branched-chain Amino Acids (bcaa) Also Interacts With Other Medications

Branched-chain Amino Acids (bcaa) has 5 major, 85 moderate known drug interactions in our database — the Insulin Aspart one above is one of them. If you take anything else, check it against the full list below.

Major 5 Moderate 85 No known interaction 2,740 (incl. Insulin Aspart)
Taking anything else?

Check Another of Your Medications Against Branched-chain Amino Acids (bcaa)

Covers the 2,830 medications we’ve checked against Branched-chain Amino Acids (bcaa). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Insulin Aspart

This page covers Branched-chain Amino Acids (bcaa) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Insulin Aspart page lists 239 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate), Agaricus Mushroom (moderate) and Agmatine (moderate).

By severity: 1 major · 208 moderate · 30 minor.

From our pharmacist’s overview on the Insulin Aspart page

“Every one of the 239 supplements listed for insulin aspart (Fiasp) touches the same thing the drug exists to manage, blood sugar, so this list warrants genuine care rather than a quick skim. Most entries add to insulin's glucose-lowering effect, raising the risk of hypoglycemia, and with a rapid-acting mealtime insulin a low can become…”

Reviewed by 2 · Jul 18, 2026

Open the Insulin Aspart interaction page

How much people look this up

Where Branched-chain Amino Acids (bcaa) and Insulin Aspart Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Branched-chain Amino Acids (bcaa)
Steady interest

#1,166 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Insulin Aspart
Top half

#934 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Branched-chain Amino Acids (bcaa)

What is Branched-chain Amino Acids (bcaa)?

  • Muscle building and exercise recovery
  • Reducing exercise fatigue
  • Preserving muscle during weight loss
  • Liver disease support
  • Tardive dyskinesia (under study)

Branched-chain amino acids (leucine, isoleucine, and valine) are essential nutrients commonly taken by athletes for muscle support and recovery. Evidence shows modest benefits for some uses, but a balanced protein source usually provides the same amino acids. They are generally well tolerated for most healthy adults, but check with your pharmacist or doctor before use, especially if you have a medical condition.

Read the full Branched-chain Amino Acids (bcaa) monograph & all interactions
Medication

About Insulin Aspart (rDNA Origin) Injection

What Is Insulin Aspart (rDNA Origin) Injection Used For?

Brand name: Fiasp

Insulin aspart is used to improve blood sugar (glucose) control in people with diabetes mellitus. It is approved for both type 1 and type 2 diabetes in adults, and for diabetes mellitus in pediatric patients.

Insulin Aspart Protamine and Insulin Aspart Mix 70/30 is a pre-mixed product that combines a rapid-acting and an intermediate-acting insulin aspart. It is approved to improve blood sugar control in adult patients with diabetes mellitus. It is not recommended for treating diabetic ketoacidosis, and because its ratio of rapid-acting to intermediate-acting insulin is fixed, it does not allow for separate mealtime versus background dose adjustments.

See full Insulin Aspart (rDNA Origin) Injection drug information
Keep checking

Other Drugs & Branched-chain Amino Acids (bcaa)

Browse every other medication we’ve checked against Branched-chain Amino Acids (bcaa) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

5Major
85Moderate
0Minor
2,739No known interaction
5 Major 85 Moderate 2,739 No interaction
Major

5 interactions

Moderate

85 interactions

Showing 60 of 85 moderate interactions — see all 85 on the Branched-chain Amino Acids (bcaa) page.

No interaction 2,739 drugs checked — show the list

We also checked Branched-chain Amino Acids (bcaa) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,739 medications checked with no known interaction — see the full Branched-chain Amino Acids (bcaa) list.

See the full Branched-chain Amino Acids (bcaa) interactions page
See every supplement checked against Insulin Aspart, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Branched-chain Amino Acids (bcaa) monograph › Uses, safety, and every drug interaction in one place Insulin Aspart supplement interactions › Every supplement checked against Insulin Aspart, ranked by severity Insulin Aspart (rDNA Origin) Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Branched-chain Amino Acids (bcaa) and Insulin Aspart Together: Common Questions

Can you take Branched-chain Amino Acids (bcaa) with Insulin Aspart?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Branched-chain Amino Acids (bcaa) and Insulin Aspart interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Insulin Aspart and Branched-chain Amino Acids (bcaa)?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.