Bicillin shortage in pregnancy: what Lentocilin means now

If you are pregnant and have been told you need treatment for syphilis, the main takeaway is simple: do not delay getting connected with care because of the Bicillin L-A shortage. Federal health officials say the shortage is ongoing, and the FDA has allowed temporary importation of Lentocilin to help address part of the gap.

For patients, the most important point is that benzathine penicillin G remains the only recommended treatment for syphilis during pregnancy. If a clinic mentions Lentocilin, that does not automatically mean you are being offered the wrong medicine. It means your care team may be using a temporarily imported formulation of the same antibiotic ingredient, with different labeling, preparation, and handling requirements.

Why this shortage matters so much in pregnancy

CDC says benzathine penicillin G is the only recommended treatment for syphilis during pregnancy. That is why public health agencies have urged health systems to preserve limited supply for pregnant patients whenever possible.

This matters because untreated or inadequately treated syphilis during pregnancy can infect the fetus and lead to congenital syphilis. MedlinePlus describes congenital syphilis as severe, disabling, and often life-threatening. Babies may appear normal at birth and still develop serious problems later, including hearing loss, blindness, bone abnormalities, or nervous system complications.

That is also why timing matters. ACOG recommends syphilis screening at the first prenatal visit, with repeat screening during the third trimester and again at birth. If a pregnant person tests positive, starting and completing treatment promptly is a major part of preventing harm to the baby.

What is happening with Bicillin L-A now

CDC posted an update on April 23, 2026, saying Bicillin L-A remains in limited supply in the United States. The same update said that, as of April 14, 2026, the manufacturer had pushed the next delivery of two commonly used adult Bicillin L-A syringe strengths to October 2026, with anticipated recovery moved to the fourth quarter of 2027.

That means this is not a brief disruption. Depending on where you live, your clinic, hospital, pharmacy, or local health department may still be actively managing access and prioritizing supply for pregnancy-related treatment.

What Lentocilin is

Lentocilin is another formulation of benzathine penicillin G. The FDA says it is not FDA-approved, but the agency is allowing temporary importation during the shortage.

For patients, that can sound alarming. In this setting, “not FDA-approved” does not mean the product is counterfeit or being used informally. It means the FDA is allowing a non-U.S. product to be imported under shortage-related oversight because regular U.S. supply remains limited.

How Lentocilin differs from Bicillin L-A

The FDA’s temporary importation notice describes several differences that are mostly important for clinicians, pharmacists, and health systems, but patients may notice them too.

The packaging and labeling are different. Lentocilin has foreign, non-U.S. labeling, so the carton may not look like standard U.S. Bicillin L-A.
It is not a prefilled syringe. Lentocilin is supplied as powder plus diluent and has to be prepared before use.
It must be given by deep intramuscular injection. Route matters, and the imported product does not use the same standard U.S. warning format as Bicillin L-A.
The injection volume can differ. After reconstitution, 1.2 million units of Lentocilin is about 4 mL, compared with 2 mL for the comparable Bicillin L-A strength.
It contains soy phospholipids. That may matter for people with a soybean allergy or a prior serious soy-related hypersensitivity reaction.
Barcode and tracing information may not work the same way in U.S. systems. This is mainly a clinic and pharmacy safety issue, but it is one reason staff may double-check documentation.

Those differences do not mean patients should refuse care on their own. They do mean clinics need to follow the FDA notice carefully so the right product is prepared, documented, and administered the right way.

What this means for patients and families right now

If you are pregnant and a clinician says you may have syphilis, or if a sex partner has been diagnosed, it is reasonable to treat this as time-sensitive. Do not assume you can wait until the next routine prenatal visit.

Helpful questions to ask include:

Do you have Bicillin L-A available, or are you using Lentocilin during the shortage?
If you are using Lentocilin, will anything about my appointment or injection schedule be different?
If the product is not available here today, where should I go next?
Do I need help coordinating treatment through the local health department, STI clinic, hospital, or another site?
If I have a history of penicillin allergy or soy allergy, does that change the plan?
When should follow-up blood tests or repeat visits happen?

Access may vary by state, health system, and clinic. Some pregnant patients may be referred to public health programs, hospital-based clinics, or other sites that still have supply.

If a baby is born before maternal treatment is complete, or a clinician says the newborn may have been exposed, ask the pediatric team right away what evaluation or treatment is needed. CDC says penicillin is also the only recommended treatment for babies with congenital syphilis.

Why experts worry about delays

A peer-reviewed Obstetrics & Gynecology study looked at syphilis treatment during pregnancy across six U.S. states from 2018 through 2021. It found that inadequate or no treatment during pregnancy still occurred for multiple reasons. The study was observational, and it predates the current Lentocilin importation, so it does not prove that today’s shortage will directly cause missed treatment. But it does reinforce a practical point: when treatment is delayed, interrupted, or not completed correctly during pregnancy, babies can remain at risk.

What remains uncertain

Several things are still not fully clear for the public. Local availability can change quickly. Not every site will have the same access to Bicillin L-A or Lentocilin. And although federal agencies have laid out a path to stretch supply, it is not yet clear whether recovery will happen sooner than current projections.

That is why individual logistics matter so much. A treatment plan that works in one county or hospital system may not be the same in another.

When to seek care quickly

Contact your prenatal clinician, STI clinic, or local health department promptly if you are pregnant and:

you were told a syphilis test was positive or needs confirmation,
a sex partner was diagnosed with syphilis,
you missed a scheduled treatment visit,
you were told a needed injection is unavailable at your usual clinic, or
you have a history of penicillin allergy or soy allergy and treatment planning is being delayed.

Seek emergency help right away if you have signs of a serious allergic reaction after an injection, such as trouble breathing, swelling of the face or throat, or widespread hives.

The bottom line

The Bicillin L-A shortage is still affecting pregnancy care in the United States, and CDC continues to treat pregnant patients as the highest priority group for available supply. Lentocilin gives clinicians another way to provide benzathine penicillin G during the shortage, but it is not a simple one-for-one swap in packaging or handling.

For patients, the safest next step is not to self-decide between products. It is to stay in close contact with a qualified clinician and, if needed, ask for help finding a site that can provide treatment without delay.

Sources

Editorial note: Weence articles are researched from cited public-health, medical, regulatory, journal, and reputable news sources and may be drafted with AI assistance. They are checked for source support, clarity, and safety guardrails before publication.

This article is for general informational purposes only and is not medical advice. Research findings can be early or incomplete, and health guidance can change. Always talk with a qualified healthcare professional about personal symptoms, diagnosis, medications, vaccines, screenings, or treatment decisions. If you think you may have a medical emergency, call emergency services right away.